Thanks again Neiko!
Repuk goes Reverse Osmosis
Really, really happy with the RO system outcome.
Mine is Yatek brand, but it's based on a NW-RO50-A3QF
, by Chinese OEM maker Yuyao Yadong Plastic who seems to manufacture 80% of RO systems; only difference on mine is Yatek fitted a better controller, with auto-flush.
would be a suitable model for our purpose (with controller + auto-flush).
No need to look for exactly the same, you will be able to find a similar system for less than $150 (including filters and membrane, fittings,) etc... just make sure it has auto-flush, and controller. Most sellers will just rebrand the Yuyao Yadong ones, mix and match some parts between models, etc so don't be worried if you see same system being sold for $100 or $250 or almost $400...
I spent 132€ total, including the aquarium float shutoff valve (7€):, system is completely automated and is able to produce 50gal+/200L+ per day, shutting off automatically when the 200L drum is full. Only drawback so far is the controller seems to have a safety mechanism built in and will stop after purifying 100L non stop... not a big deal, though will look if it can be fixed.
Using a system with integrated or "booster" pump is essential, otherwise the ratio of ro/waste water would be off and unpredictable, 1:3, or even worse. I checked this: took two glasses and put one collecting ro and the other waste for a couple minutes; both glasses had the same water volume, so yield is 1:1, i.e. per each 1Gal of RO water, 1 gal of "dirty" water is produced.
The second important thing is Automated control. Thanks to the electronic controller, membrane flush/wash cycles are completely automatic; and most important, it adds the safety of having high/low pressure sensors, which is the basis for the unpressurized reservoir drum float shutoff valve to work (controller will sense high pressure returned from the closed float valve and will shutoff the RO unit automatically).
You won't need the pressurized tank nor the faucet, so look for incomplete kits on offer, returns, kits with no tanks, or scratched tanks, etc to save.
Install the filters in their respective cartridges: first the sediment filter on C, Granular carbon filter on E, Block carbon filter on F.
Install the membrane. The side with two rubber gaskets goes in first.
Mine is a 5 stage system, but I modified it to be a 4 stage one by omitting the fifth, which is usually a carbon filter (P) to enhance taste, which we neither need nor will spend on replacements simplifying the whole setup. Faucet (Q) is not used either, nor the pressurized storage tank/valve (N/M): the reddish shadowed area is omitted.
- Connect water input (1).
- Instead of connecting the "clean water" membrane output (3) to the 12L pressurized tank (N), membrane clean output (3, after K) goes directly to the drum through an aquarium float valve, which also uses quick fittings (JACO) connectors.
- Drill the barrel/drum at desired water level, fix the float valve, and connect the hose coming from (3) to it through the quick-fit connector.
- Leave the quick-fit JACO connector (4, the one going to the faucet) with the shipping plug.
- Connect membrane waste output (2) to the drain, or to a drum if you'll be using that water for yard irrigation, etc.
Water input connected, fittings included with kit; use tons of teflon tape and find the best accomodation while being tight:
Shutoff Valve view from outside:
Float Valve view from inside: plastic shim + rubber gasket goes on same side where water is:
Once assembled, you can play with the "Elbow" angle the Float ball makes versus the stem by manually applying force.
Depending on drum "mouth", look and test for strategical placement of the float valve so that is possible to slide a regular bucket inside the drum for quick fills.
Thought on making it smaller with a ping pong ball or similar.
So to summarize, once the system is started, it will:
1.- Do a membrane Wash/flush cycle
2.- Start producing water
3.- Do a membrane flush cycle each two hours
4.- once open reservoir fills, float valve will shut the output, and the controller will stop the system signaling the reservoir as "Full".
Water out of my tap is PH9 right now, EC 0.4-0.5.
I collect the waste water produced (0.6EC) to water the trees and grass.
The produced RO water is EC 0.05, PH 7.6, barely need to "show" the 60% Nitric Acid bottle to lower the whole reservoir to 6.2-6.5, for the outdoors plants on soil.
I just mixed the first tank using RO for the Panama and Malawi girls; while on previous weeks with tap water I had to use almost 7ml of 60% nitric acid (a no-no on hydro/100% salts with flowering girls!), and PH wasn't stable at all, slowly drifting/raising, this time I needed less than 1/4ml of 60% nitric acid to lower PH of the indoor 100L reservoir to 5.6 stable (only water)... possibly wouldn't need any if I would have mixed the salts first... will see next time.
Really, really happy. I have witnessed what good water produces (managed to pull an almost 100% rain water grow) and ain't looking back...