RO-DI system?

[SirRoadwolf]

I am seeing various systems available which suggest 50+ gal / day filtration. I'd imagine the higher output = less pure filtration?

I also wonder if I should get the manual flush version, or not? What is the difference?

I plan on hooking this up to an automated RTO system. So I imagine there will eventually be electronic valves controlling the flow through this unit.

 

[Idoc]

BRS has a 4 stage system that has an output of 75g per day. I have one of these systems and don't get anywhere breast that output, but my water pressure is very low. Basically you get 1 gal RODI water for every 3-4 gal waste. If thou put on a pump to raise the water pressure and/ot add another RO membrane, the output is better with less waste water.

BRS also had all the fittings you need to automate the system... plus good videos on how to hook it all up. I use a manual flush now... easy to let it run a few minutes before and after you flush the membrane.

 

[redfishbluefish]

First off, differences in output doesn't impact purity. That's determined by the ejection of the membrane. Good membranes are 98% or better with ejection.

I'm assuming you meant ATO...with direct connection to the RO/DI. I strongly would not recommend this. The reason is that every time the RO/DI starts up, there is breakthrough TDS. With an ATO, that could be every 15 - 30 minutes. This will cause for premature failure of the DI resin.

When I make good water, I divert the first five minutes of water to eliminate breakthrough, before I switch the valve to make good water. Then I make good water for hours. I use the diverter valve from BRS to "clear" the TDS breakthrough for the first five minutes of startup.

 

[mfinn]

Some other brands to look at besides brs would be, Spectrapure, Buckeye Hydro, and Melev's Reef.
I just bought the Melev's Reef RODI.

 

[Steve Jewell]

I just posted this on another post but will copy it in here. Here is my setup and it is AWESOME!! Plus you get tank and faucet for your own use.

If you want to save some $$ and get a kick *** RO/DI setup, here's how I did it!!
https://www.ebay.com/itm/142676621889?ViewItem=&item=142676621889
This is the 5 stage under sink RO system 75 gal from RD Aqua. I wanted something both useful in home and for the aquarium (the wife will LOVE IT!!) It comes with enough filters for a couple years and is producing 28 TDS water at the faucet. (On my DI unit the input says 3 tds?? hmmm) $138.99
I also purchased a dual DI unit that I plumbed right by my mixing station.
https://www.amazon.com/gp/product/B073DHYWTF/ref=od_aui_detailpages00?ie=UTF8&psc=1
This dual stage DI comes with TDS meter for $79.99 and I am producing 0 TDS water. So far 300 gal and barely used any resin.
I added on a pressure meter for 11.49 from Amazon and a flush valve for $9.95 from Amazon.
Total price for a KICK *** system all in is around $240

 

[NeedMoreReef]

get quality unit from BRS or Spectrapure. you can't go wrong. that being said.
I have a cheap "ebay" RO/DI in use for... lets see... '99 thats um... a long time. I replace with all spectra pure membranes.
I've added a spectrapure 2 stage DI.

most units are 50-90 gallon per day. doesn't impact quality. you wont get that much water (and don't need that much) unless you have boost pump anyways.
Don't hook your RO/DI directly to your tank. fill a reservor and have that replace evap via a high quality ATO.
manual flush is nice... I don't have one though. I think really high end spectra pure units have automated flush, but not sure.

 

[PatW]

I have a 6 stage BRS unit. It is 75 gpd and is actually a bit better than that. TDS goes in at about 140 and out at 1 or 2. BRS has a scad of you tube videos. Operation. Is pretty easy. I would suggest getting a unit with the ability to measure TDS post membrane and post DI resin. Having the ability to flush is good too. I use a Brute trash can for RODI storage. BRS has a cheap little float valve to turn off the unit instead of flooding the house when I inevitably forget to check it in time. I like my BRS system and it works fine. However, Spectrapure owners verge on being fanatics. There must be a reason for it.

 

[Long Tran]

Is the Ispring from amazon here gonna work too? For drinking and aquarium?

 

[redfishbluefish]

Is the Ispring from amazon here gonna work too? For drinking and aquarium?

Yes it can work, with modification.

1. You don't want to use the tank water on this system for your fish tank....it has some TDS from breakthrough from constantly turning on and off to keep that pressure tank full. So you'll need to install a valve to redirect the water to whatever you wish to collect water for your aquarium.

2. This unit does not come with a DI canister, so that would have to be added to this unit as well, and installed after the valve redirecting water away for the pressure tank.

3. You also want to avoid the re-mineralization filter. And my opinion is that the UV sterilization is a waste of money.

Hope this is understandable.

 

[Ironwill723]

Check out the Vertex 100 and 200gpd RODI units. I have the 200gpd unit. Works great.

 

[kkeller416]

Brs has a great video explaining how the rodi unit works and why you need flush valves, if your water pressure is low..you may need a booster pump them you can install a automatic flush valve.
I think the most important part of buying a system is understanding what and why your buying it. If you have a small tank your making water for vs a 200g tank your making water for will determine what you need to buy.

 

[SirRoadwolf]

Very basic and quickly done sketch of my planned setup.

Basically I use a water level switch to activate a relay and a 3 minute timer relay at the same time. The timer relay switches another relay which opens a valve from the RO/DI to a drain, which in turn allows the water to flush out. Then after 3 minutes, the relay turns off, switching to the normally closed option, which opens the valve to the ATO... once full, it shuts the valve when the water level rises enough to activate the level switch again. Notice, also the ability to have a manual tap to flush / use the water.