Too much water or more accurately too diluted of nutrient solution is something I hadn't considered before. Lot's of great information in the video and comments! Two questions. Does the nutrient concentrate need to flow directly over roots to properly uptake? I’m assuming this is why water turn-over rates are important, to ensure nutrient concentrate is available to the plant roots. Is this also why a 200mg/L minimum nutrient solution is required to maintain plants (for "root pressure" - assuming the concentrate is pressed into the roots)? The reason for the first question is that I plan on having several wicking grow beds in my AP system and am concerned that the plants won’t properly uptake the nutrients from the water.
OK, some really good conversation going on here. Lets see if we can add to it. We talk as though the feed we add to the system is going strait to the plants and skip the fact that it has to be processed by the fish and how they and their food play into the equation. 1. If I up my food what I am really saying is I need to up my # of fish so I had better of planned my system from the start to be able to accommodate a range as I balance it or to be able to accept pants that require more nutrients e.g. tomatoes vs lettuce. 2. The way you explained the way to calculate fish in the "Revised Aquaponics Blueprint Review" based on the UVI model started with M2 grow space, then feed requirements, then Feed Conversion Ratios & Feed efficiency ratios & from there you derived the weight & subsequent # of fish required. What happens when I use a fish that is more efficient at converting the food? What happens when I use the same fish but a higher quality food? All of this ties back to my frustration with the UVI formulas. They made it simple (as long as your system looks exactly like theirs). Unfortunately simple comes at the cost of flexibility when it comes to being able to readily adapt a system to all the different variables.
You mentioned that 200 PPM is the optimal concentration for growing lettuce in a standard DWC System. What are those 200 PPM made up of, or composed of? Is it all me Micro and Macro nutrients that you need? What im trying to ask is if you measured all of the nutrients in ppm in your system and added them together should that give you 200 total? Thats what I understand as of right now, if my understanding is correct what are the ppm (or concentrations) that i have to keep for each of the nutrients needed to grow a lettuce un a Standard DWC system? Having the ppm of each nutrient would really help me out a lot. Hope you read and answer. Great videos btw, thanks for the info.
great content, thanks. what are the total assumptions of the recommended concentrations? i.e. 1m2 of raft bed that is X deep + fish tank volume necessary to house fish at Y capacity (0.5lb/gallon?) consuming the calculated amount of feed? my only suggestion would be to add to the video description the Amazon links through their promo program to the cited resources for the possibility of a little side income from clicky.
What if the plants drink the water? Just replacing the missing water, does not return the saturation level of the fluid. the plants also consume or retain the concentration. So both water and concentration must be replenished. How do you determine the amount consumed?
Ooooh this is a really useful video! :-D From watching your other videos about DWC, NTF and a couple of systems analyses where you gave feed/volume comparison between DWC, grow beds, NFT and towers, I came up with: DWC: 60-100 grams of feed per m2 per day: 60-100 g/m2/d NTF/VT: 65%-75% less volume so less feed: 42-70 g/m2/d F/D bed: 40-50% less (volume like DWC but there’s gravel): 30-50g/m2/d Do you think this is correct? Also, can you confirm that a vertical tower can be considered as an NTF tube? Finally... wouldn't it be simpler to simply calculate the total amount of water in the system, set the feed quantity needed to keep it at a desirable concentration for what you're growing, then from that decide how many fishes you can grow? I would also assume that the number of plants doesn't matter much in the end (at least until you have a hectare...) since the extra nitrates will be consumed by bacteria and algae too if plants don't take them: am I correct in this? EDIT: just read your previous answer here, so no, you need to have enough plants! Thanks again for your videos and comments, I find them really helpful in trying to understand how to design a decent system!
Hey Roberto, Woooo!!! I'm glad you're enjoying the videos. Here is my feed back1.DWC: 60-100 grams of feed per m2 per day: 60-100 g/m2/d This is correct and the standard ratio for DWC 2. NTF/VT: 65%-75% less volume so less feed: 42-70 g/m2/d This is somewhat correct and may vary. Dr. Rakocy recommends 75% decrease (This was an approximation from him and not actual tested amount) which is 15 - 25g/m2/day, but from my experience the ratio is more closely related to 60-65% decrease which is 21-24g/m2/day (low end for lettuce, etc) to 35-40g/m2/day(high end for tomatoes, cucumbers, etc) 3. F/D bed: 40-50% less (volume like DWC but there’s gravel): 30-50g/m2/d This ratio assumes that the sump tank is designed the way we calculated in our sump calculation video. It also assumes that the solids are removed before they enter the bed because if the solids breakdown in the system they add extra nutrients to the system which throughs off the feeding ratio. If you let solids remain in the system then there is an alternative way that Dr. Lennard has computed to account for the extra mineralization. Here is the calculator for this situation. www.aquaponic.com.au/calculators.htm 4. Do you think this is correct? Also, can you confirm that a vertical tower can be considered as an NTF tube? Yes, it should be calculated the same way. NFT and vertical systems both use very similar flow rates, so you should calculate based off of NFT. Vertical is basically an NFT system that is standing up. That's how you should view it. 5.Finally... wouldn't it be simpler to simply calculate the total amount of water in the system, set the feed quantity needed to keep it at a desirable concentration for what you're growing, then from that decide how many fishes you can grow? I would also assume that the number of plants doesn't matter much in the end (at least until you have a hectare...) since the extra nitrates will be consumed by bacteria and algae too if plants don't take them: am I correct in this? EDIT: just read your previous answer here, so no, you need to have enough plants! Lol yes, you need to have the correct amount of plants to balance the system or you will eventually have toxicities or deficiencies. The way that I have shown how to calculate the system components is the easiest way to do it. You do not want to start your calculation with a set water volume in mind but rather a set number of fish or plants and then work from there. It's much easier.
I love your videos. Maybe I am missing something. It seems like the answer you gave doesn't apply to the question. I watched the video twice. I think he was asking once the system is in full production, do you just replace the nutrients that are taken out? Did I miss something?
Hey Scott, so here is his question "E.g. [Simplified] If your plants take up nutrients of 60gr of fish feed/day (1 m2) and you have 2x the amount of water in your system compared to the 'standard' DWC as explained in this video, you would need to feed your fish 120gr of feed. This means supplying 60gr of excess nutrients to the system. Won't these nutrients build-up over time?" The question assumes that doubling the water volume and nutrients would cause an excessive amount of nutrients, so the objective of this video was to try and explain how it is a MUST to double the feed if you double the water or else the nutrients would be diluted. The recommended feeding rate for DWC and lettuce is 60g/m2/day, and this only leaves a very LOW concentration in the system. To double the water volume and not double the feed would create even lower concentration.To maintain the same nutrients concentration (as the standard DWC) you would need to double the water volume AND feed, which would not cause any excessive nutrients. This is contrary to his assumption of having excessive nutrients that build up overtime. Let me know if you need any clarification on any other parts.
Thanks for taking time to answer my questions. Here is where I am confused. lets say I have 2 systems, one with 1,000 gal and one with 2,000 gal. both have the same concentration of ions per gallon. In each system I have a plant nutrition requirement of 60 gr per day. Now if I feed 120 to a 2000 gal system, what is happening to the ions that aren't being taken from the system? How is it that the total amount of ions and the concentration not correlated? I am thinking of it like thermodynamics. If I supply more to a system than what is being taken out, how does that not cause increased ion concentration in a system? I'm sorry if this is a stupid question.
What if you double the water in the system by adding more water that had the same concentration? This is hypothetical. So now you have double the water with the same concentration to start with. I feed 60gr to one system and 120 to an identical system. Both with plant nutrition requirements of 60gr. What happens to both systems? I am thinking of it like thermodynamics. If I am supplying more ions to a closed system than I am removing from that system, I would expect some build up. Thanks again. You are the man.
The first think you must understand is that 60g/m2/day is not the amount of nutrients to supply any plants, it's a variable ratio that only works in a given amount of water (DWC). You need to look at it as 60g/m2/day is required for the water volume of a DWC to concentrate the nutrients to levels that plants can use, while maintaining a balance of nutrient input and nutrient uptake. You can't just say 60g of feed per square meter of plants because that is only part of the equation. The water volume MUST be considered. When we grow in NFT systems this ratio doesn't work because the water volume is significantly less. 60g/day for a DWC system is designed to grow 1 square meter of lettuce and balance the nutrient input and uptake, so there is not necessarily any excessive nutrients that build up over time. Here are a few examples that hopefully help out. If not then keep asking and we can discuss further. These are hypothetical systems, but we will assume that system 1 is the standard system that creates a balance between feed input and plant uptake. System 1. (DWC) 1000 gallons x 1 square meters of plants x 60/g/m2/day = 200 ppm constant nutrient concentration. This system will be balanced and create NO excessive nutrients over time. This is how a properly balanced system should look; the nutrient input should match the nutrient uptake and the ppm in the system should remain relatively stable within a given range (realistically will be from 200-500, but will remain stable). If you double the feed input and DO NOT double the plant production area then you will experience an imbalance because the input of nutrients will exceed the uptake rate of the plant production area. System 2. (DWC)1000 gallons x 1 square meter of plants x 120g/m2/day = 400 ppm and will eventually keep climbing overtime and reach toxic levels if more plants are NOT added to balance this system. You will have to resort to water changes similarly to hydroponics in this situation as the nutrients begin to accumulate to 2,000 ppm. If you double the water volume and DO NOT decrease the plant production (in half) OR do not double the feed input then the nutrient uptake rate will exceed the nutrient input rate which will cause deficiencies. The doubled water volume will not allow the 60g to concentrate fast enough to supply all of the plants simultaneously. Remember that the 1,000 gallon in system 1 created a steady balance of 200 ppm with 60 grams feed. If you double the water volume and keep the feed input and plant production the same, then it will be IMPOSSIBLE to maintain 200 ppm which is the minimum ppm your system should have. System 3. (DWC) 2000 gallons x 1 square meter of plants x 60/g/m2/day = 100 ppm (will increase competition for nutrient uptake since the plant will be competing for the low nutrient concentration. If you double the water volume AND double the plant production AND double the feed input then you will have a balanced system. You can view this as simply having 2 separate 1,000 gallons systems. It's the same thing. No excessive nutrients will build up since each potion of the equation was equally scaled (plant, feed, and water volume) System 4. (DWC) 2000 gallons x 2 square meter of plants x 120g/m2/day = 200ppm (everything has been proportionally scaled up, therefor no change in nutrient concentration will occur from the standard DWC system) Conclusion. 60g/m2/day (for lettuce) was designed to create a balance (nutrient input=nutrient uptake) for the volume of water in a DWC system. If you significantly alter ANY variable in the equation i.e plant production area, feed input, or water volume, and do not correctly alter at least 1 other variable, then you WILL create a significant imbalance. It is impossible to alter ONLY one portion of the equation and expect to maintain a balance.
When you double the water do you double the fish? This is the problem I'm having. I have a bucket (water) and I need to keep half full of balls (nutrients). Half full is 200 balls. every day my dog (plants) takes out 5 balls per day. Now I get a bucket twice the size. I put 400 balls in it to fill it half way. I would still put in 5 balls per day. What lesson did I miss? I have a small soil garden btw. Just trying to understand.
Hello sir. Is there a way that I could contact you directly. I live in Peru South America. I am a missionary that has an Aquaponics system. 2 IBC and an aquarium with grow beds, but I can foresee problems. I would like to talk and get a pro to help.
Nice video man.Am wondering though, if the concentration has to be kept constant, doesnt it mean if I double the water then I have to double the number of fish too coz, fish can eat soo much but there will be lots of uneaten food in the tank all the time. and i think from the remains the nutrients are still loocke in. Am I correct or biscuit headed to think like this?
That is absolutely correct Joe. If you doubled the water volume, you would double the fish, feed, and the plant area as well. Then the system would be balanced again. No biscuit headed thinking on your part!
The reason am asking is coz of the question I posted on the discussion part of the channel. I have been twicking my system for the past 4 years using your ideas and it works like a swis watch. I am convinced with the knowledge you give us one can set a system to produce either more plant or more fish if they wanted to. I have decided to jump deep end and make one where fish is the main product and plants are the extra buck. I really appriciate your quick and precise answers. you are really helping many people than you will ever know.
Interesting! Your objective of catering to the fish more than the plants is actually the same objective that guys like Dr. Rakocy had when they first began experimenting with aquaponics. These guys were primarily aquaculturalist, and the plants were intended to be secondary to fish production. It just so happened to be that they were able to grow a large amount of plants using only a relatively small amount of fish, so they figured why not make money on the plants too. Good luck with your project and keep everyone updated on your results.
Too much water or more accurately too diluted of nutrient solution is something I hadn't considered before. Lot's of great information in the video and comments!
Two questions.
Does the nutrient concentrate need to flow directly over roots to properly uptake? I’m assuming this is why water turn-over rates are important, to ensure nutrient concentrate is available to the plant roots. Is this also why a 200mg/L minimum nutrient solution is required to maintain plants (for "root pressure" - assuming the concentrate is pressed into the roots)?
The reason for the first question is that I plan on having several wicking grow beds in my AP system and am concerned that the plants won’t properly uptake the nutrients from the water.
I think the soil should alredy have nutrients it just wicks the water up and moist the soil.
OK, some really good conversation going on here. Lets see if we can add to it. We talk as though the feed we add to the system is going strait to the plants and skip the fact that it has to be processed by the fish and how they and their food play into the equation.
1. If I up my food what I am really saying is I need to up my # of fish so I had better of planned my system from the start to be able to accommodate a range as I balance it or to be able to accept pants that require more nutrients e.g. tomatoes vs lettuce.
2. The way you explained the way to calculate fish in the "Revised Aquaponics Blueprint Review" based on the UVI model started with M2 grow space, then feed requirements, then Feed Conversion Ratios & Feed efficiency ratios & from there you derived the weight & subsequent # of fish required. What happens when I use a fish that is more efficient at converting the food? What happens when I use the same fish but a higher quality food?
All of this ties back to my frustration with the UVI formulas. They made it simple (as long as your system looks exactly like theirs). Unfortunately simple comes at the cost of flexibility when it comes to being able to readily adapt a system to all the different variables.
You mentioned that 200 PPM is the optimal concentration for growing lettuce in a standard DWC System. What are those 200 PPM made up of, or composed of? Is it all me Micro and Macro nutrients that you need? What im trying to ask is if you measured all of the nutrients in ppm in your system and added them together should that give you 200 total? Thats what I understand as of right now, if my understanding is correct what are the ppm (or concentrations) that i have to keep for each of the nutrients needed to grow a lettuce un a Standard DWC system? Having the ppm of each nutrient would really help me out a lot. Hope you read and answer. Great videos btw, thanks for the info.
Thats some very rare explanation very hard to find elsewhere, keep it up and thanks.
P.s: Great drawings in all your videos haha
Thanks a lot!
great content, thanks. what are the total assumptions of the recommended concentrations? i.e. 1m2 of raft bed that is X deep + fish tank volume necessary to house fish at Y capacity (0.5lb/gallon?) consuming the calculated amount of feed?
my only suggestion would be to add to the video description the Amazon links through their promo program to the cited resources for the possibility of a little side income from clicky.
What if the plants drink the water? Just replacing the missing water, does not return the saturation level of the fluid. the plants also consume or retain the concentration. So both water and concentration must be replenished. How do you determine the amount consumed?
Hello,,,
I have a question about kinds of fishes that can be raised together in one tank . for home use and small aquaponic system.
thank you...
Nice video. Where can I buy your book?
Ooooh this is a really useful video! :-D
From watching your other videos about DWC, NTF and a couple of systems analyses where you gave feed/volume comparison between DWC, grow beds, NFT and towers, I came up with:
DWC: 60-100 grams of feed per m2 per day: 60-100 g/m2/d
NTF/VT: 65%-75% less volume so less feed: 42-70 g/m2/d
F/D bed: 40-50% less (volume like DWC but there’s gravel): 30-50g/m2/d
Do you think this is correct? Also, can you confirm that a vertical tower can be considered as an NTF tube?
Finally... wouldn't it be simpler to simply calculate the total amount of water in the system, set the feed quantity needed to keep it at a desirable concentration for what you're growing, then from that decide how many fishes you can grow?
I would also assume that the number of plants doesn't matter much in the end (at least until you have a hectare...) since the extra nitrates will be consumed by bacteria and algae too if plants don't take them: am I correct in this? EDIT: just read your previous answer here, so no, you need to have enough plants!
Thanks again for your videos and comments, I find them really helpful in trying to understand how to design a decent system!
Hey Roberto, Woooo!!!
I'm glad you're enjoying the videos. Here is my feed back1.DWC: 60-100 grams of feed per m2 per day: 60-100 g/m2/d
This is correct and the standard ratio for DWC
2. NTF/VT: 65%-75% less volume so less feed: 42-70 g/m2/d
This is somewhat correct and may vary. Dr. Rakocy recommends 75% decrease (This was an approximation from him and not actual tested amount) which is 15 - 25g/m2/day, but from my experience the ratio is more closely related to 60-65% decrease which is 21-24g/m2/day (low end for lettuce, etc) to 35-40g/m2/day(high end for tomatoes, cucumbers, etc)
3. F/D bed: 40-50% less (volume like DWC but there’s gravel): 30-50g/m2/d
This ratio assumes that the sump tank is designed the way we calculated in our sump calculation video. It also assumes that the solids are removed before they enter the bed because if the solids breakdown in the system they add extra nutrients to the system which throughs off the feeding ratio. If you let solids remain in the system then there is an alternative way that Dr. Lennard has computed to account for the extra mineralization. Here is the calculator for this situation. www.aquaponic.com.au/calculators.htm
4. Do you think this is correct? Also, can you confirm that a vertical tower can be considered as an NTF tube?
Yes, it should be calculated the same way. NFT and vertical systems both use very similar flow rates, so you should calculate based off of NFT. Vertical is basically an NFT system that is standing up. That's how you should view it.
5.Finally... wouldn't it be simpler to simply calculate the total amount of water in the system, set the feed quantity needed to keep it at a desirable concentration for what you're growing, then from that decide how many fishes you can grow?
I would also assume that the number of plants doesn't matter much in the end (at least until you have a hectare...) since the extra nitrates will be consumed by bacteria and algae too if plants don't take them: am I correct in this? EDIT: just read your previous answer here, so no, you need to have enough plants!
Lol yes, you need to have the correct amount of plants to balance the system or you will eventually have toxicities or deficiencies. The way that I have shown how to calculate the system components is the easiest way to do it. You do not want to start your calculation with a set water volume in mind but rather a set number of fish or plants and then work from there. It's much easier.
Thank you so much! :-)
LOL, instead of 65-75% less I did a 65-75% of the total ^^;;;;;
Thanks again
Lol yep I noticed that, but it was a reasonable mistake. Thanks for watching!
What is the difference of aquaponics and hydroponics
The addition of fish
WOOOOOOOO!!!!! ✊🏾
I love your videos. Maybe I am missing something. It seems like the answer you gave doesn't apply to the question. I watched the video twice. I think he was asking once the system is in full production, do you just replace the nutrients that are taken out? Did I miss something?
Hey Scott, so here is his question
"E.g. [Simplified] If your plants take up nutrients of 60gr of fish feed/day (1 m2) and you have 2x the amount of water in your system compared to the 'standard' DWC as explained in this video, you would need to feed your fish 120gr of feed. This means supplying 60gr of excess nutrients to the system. Won't these nutrients build-up over time?"
The question assumes that doubling the water volume and nutrients would cause an excessive amount of nutrients, so the objective of this video was to try and explain how it is a MUST to double the feed if you double the water or else the nutrients would be diluted. The recommended feeding rate for DWC and lettuce is 60g/m2/day, and this only leaves a very LOW concentration in the system. To double the water volume and not double the feed would create even lower concentration.To maintain the same nutrients concentration (as the standard DWC) you would need to double the water volume AND feed, which would not cause any excessive nutrients. This is contrary to his assumption of having excessive nutrients that build up overtime.
Let me know if you need any clarification on any other parts.
Thanks for taking time to answer my questions. Here is where I am confused. lets say I have 2 systems, one with 1,000 gal and one with 2,000 gal. both have the same concentration of ions per gallon. In each system I have a plant nutrition requirement of 60 gr per day. Now if I feed 120 to a 2000 gal system, what is happening to the ions that aren't being taken from the system? How is it that the total amount of ions and the concentration not correlated? I am thinking of it like thermodynamics. If I supply more to a system than what is being taken out, how does that not cause increased ion concentration in a system? I'm sorry if this is a stupid question.
What if you double the water in the system by adding more water that had the same concentration? This is hypothetical. So now you have double the water with the same concentration to start with. I feed 60gr to one system and 120 to an identical system. Both with plant nutrition requirements of 60gr. What happens to both systems? I am thinking of it like thermodynamics. If I am supplying more ions to a closed system than I am removing from that system, I would expect some build up. Thanks again. You are the man.
The first think you must understand is that 60g/m2/day is not the amount of nutrients to supply any plants, it's a variable ratio that only works in a given amount of water (DWC). You need to look at it as 60g/m2/day is required for the water volume of a DWC to concentrate the nutrients to levels that plants can use, while maintaining a balance of nutrient input and nutrient uptake. You can't just say 60g of feed per square meter of plants because that is only part of the equation. The water volume MUST be considered. When we grow in NFT systems this ratio doesn't work because the water volume is significantly less.
60g/day for a DWC system is designed to grow 1 square meter of lettuce and balance the nutrient input and uptake, so there is not necessarily any excessive nutrients that build up over time. Here are a few examples that hopefully help out. If not then keep asking and we can discuss further.
These are hypothetical systems, but we will assume that system 1 is the standard system that creates a balance between feed input and plant uptake.
System 1. (DWC) 1000 gallons x 1 square meters of plants x 60/g/m2/day = 200 ppm constant nutrient concentration. This system will be balanced and create NO excessive nutrients over time. This is how a properly balanced system should look; the nutrient input should match the nutrient uptake and the ppm in the system should remain relatively stable within a given range (realistically will be from 200-500, but will remain stable).
If you double the feed input and DO NOT double the plant production area then you will experience an imbalance because the input of nutrients will exceed the uptake rate of the plant production area.
System 2. (DWC)1000 gallons x 1 square meter of plants x 120g/m2/day = 400 ppm and will eventually keep climbing overtime and reach toxic levels if more plants are NOT added to balance this system. You will have to resort to water changes similarly to hydroponics in this situation as the nutrients begin to accumulate to 2,000 ppm.
If you double the water volume and DO NOT decrease the plant production (in half) OR do not double the feed input then the nutrient uptake rate will exceed the nutrient input rate which will cause deficiencies. The doubled water volume will not allow the 60g to concentrate fast enough to supply all of the plants simultaneously. Remember that the 1,000 gallon in system 1 created a steady balance of 200 ppm with 60 grams feed. If you double the water volume and keep the feed input and plant production the same, then it will be IMPOSSIBLE to maintain 200 ppm which is the minimum ppm your system should have.
System 3. (DWC) 2000 gallons x 1 square meter of plants x 60/g/m2/day = 100 ppm (will increase competition for nutrient uptake since the plant will be competing for the low nutrient concentration.
If you double the water volume AND double the plant production AND double the feed input then you will have a balanced system. You can view this as simply having 2 separate 1,000 gallons systems. It's the same thing. No excessive nutrients will build up since each potion of the equation was equally scaled (plant, feed, and water volume)
System 4. (DWC) 2000 gallons x 2 square meter of plants x 120g/m2/day = 200ppm (everything has been proportionally scaled up, therefor no change in nutrient concentration will occur from the standard DWC system)
Conclusion.
60g/m2/day (for lettuce) was designed to create a balance (nutrient input=nutrient uptake) for the volume of water in a DWC system. If you significantly alter ANY variable in the equation i.e plant production area, feed input, or water volume, and do not correctly alter at least 1 other variable, then you WILL create a significant imbalance. It is impossible to alter ONLY one portion of the equation and expect to maintain a balance.
When you double the water do you double the fish? This is the problem I'm having. I have a bucket (water) and I need to keep half full of balls (nutrients). Half full is 200 balls. every day my dog (plants) takes out 5 balls per day. Now I get a bucket twice the size. I put 400 balls in it to fill it half way. I would still put in 5 balls per day. What lesson did I miss? I have a small soil garden btw. Just trying to understand.
Hello sir. Is there a way that I could contact you directly. I live in Peru South America. I am a missionary that has an Aquaponics system. 2 IBC and an aquarium with grow beds, but I can foresee problems. I would like to talk and get a pro to help.
Nice video man.Am wondering though, if the concentration has to be kept constant, doesnt it mean if I double the water then I have to double the number of fish too coz, fish can eat soo much but there will be lots of uneaten food in the tank all the time. and i think from the remains the nutrients are still loocke in. Am I correct or biscuit headed to think like this?
That is absolutely correct Joe. If you doubled the water volume, you would double the fish, feed, and the plant area as well. Then the system would be balanced again. No biscuit headed thinking on your part!
What would happen if I don't increase the plant area,will I be in danger of nutrient build up?
Yes, overtime you could expect the concentration to slowly build up if you don't increase the plant production in that scenario.
The reason am asking is coz of the question I posted on the discussion part of the channel. I have been twicking my system for the past 4 years using your ideas and it works like a swis watch. I am convinced with the knowledge you give us one can set a system to produce either more plant or more fish if they wanted to. I have decided to jump deep end and make one where fish is the main product and plants are the extra buck. I really appriciate your quick and precise answers. you are really helping many people than you will ever know.
Interesting! Your objective of catering to the fish more than the plants is actually the same objective that guys like Dr. Rakocy had when they first began experimenting with aquaponics. These guys were primarily aquaculturalist, and the plants were intended to be secondary to fish production. It just so happened to be that they were able to grow a large amount of plants using only a relatively small amount of fish, so they figured why not make money on the plants too.
Good luck with your project and keep everyone updated on your results.
Holy shit $130 for the book. Someone get that into a chinese printing press