How to save 350 € / year

I bought a water filtration system and was pleasantly impressed, both by the degree of filtration and the savings I make.
The products I used for this system are the following:
Water filter support, wall mounting, ATLAS Filtri
www.dedeman.ro/hunedoara/supo...
Water cartridge ATLAS Filtri FA 10 - CA SX, RA5655109, 10 microns
www.dedeman.ro/hunedoara/cart...
Water cartridge ATLAS Filtri FA 10 - CA SX, 5 microns
www.dedeman.ro/hunedoara/cart...
Cartridge ATLAS Filters CB-EC VOC 10 SX, 5 mcr, RE5395108
www.dedeman.ro/ro/cartus-filt...
Brass nipple, FE-FE, 3/4", 582
www.dedeman.ro/hunedoara/nipl...
Brass reducer, FE-FE, 3/4-1/2", A580
www.dedeman.ro/hunedoara/redu...
Teflon tape for gas, 10 m x 12 mm x 0.1 mm,, 573
www.dedeman.ro/hunedoara/band... 1&idc=3993&pip=0&osa=1&upf=1
One-way flexible connection, EPDM + metal braid, with PVC protection, 1/2" - 1/4", L 600 mm
www.dedeman.ro/ro/racord-flex... 2013443&apn=1&pn=1&idc=365&pip=0&osa=1&upf=1
Flexible water connection, EPDM + metal braid, with PVC protection, 3/8" - 3/8", L 600 mm
www.dedeman.ro/ro/racord-flex... 2013480&apn=1&pn=1&idc=365&pip=0&osa=1&upf=1
At the time of purchasing the products, the NBR (National Bank of Romania) exchange rate between € and $ was approximately equal, respectively 4.88 RON = 1 € = 1 $
P.S.: I am not a professional! I'm self-taught to do these things and I don't have much experience, but I'm open and trying to improve my methods, so I greatly appreciate any feedback, advice, recommendations or constructive criticism!
0:00 Intro
2:38 Presentation of products
4:59 Installation
7:47 First commissioning
8:03 Fixing mistakes
09:23 Final commissioning
10:02 Conclusions