RO/DI so slow is it worth buying an upgrade? Do they work

Gsxkid

Well-Known Member
BRS Member
I have never owned an rodi until now and it's so slow. I have been filling off an on for like 2 days. Are the upgrade kits they sell worth it? Does it really increase water production that much?
 
Booster pumps are GREAT!!!
I'm on a Well and have low pressure (maybe 40psi).
Bought one and can get well over 100psi if needed (have it turned down to 80psi)
Usually fill a 55g drum in just about 8hrs.
 
Did you buy it new or used?

A clogged membrane will slow things down. You can clog a new one by not running the filters before it for a few minutes before attaching the RO. Flushing may help.

You might not have the correct flow restricter.

Production is also slow the colder the water is. I'm on a well and in the winter my production takes a nose dive (until I swap out the flow restricter)

And of course as the others mentioned if you don't have proper flow pressure you are just wasting your time.
 
I have had loads of different ro/di through the years. This time i got one with a booster pump. What a difference. I am making 4 gals 0tds an hr. Thats more than enough for my set up.
 
What size membrane do you have? The units themselves are pretty much all the same, the difference really lies in the cartridges and membrane. If you have decent water pressure (~80psi), just replace your membrane. They're all slow, but anything less than 90 gpd is painfully slow. You'll also need to replace the flow restrictor to match your new membrane.

If your water pressure is is low, then you should definitely consider a booster pump. Also worth noting, RODI's will fluctuate with the water temp, particularly if you're on well water. The colder the water, the slower the unit.
 
You didn't mention what GPD your membrane is rated for. If you have at least 65 PSI of pressure coming in you should be able to run at the rated GPd at 70'F. The colder water this time of year does slow it down.

If your pressure is below 65 PSI go with a booster and possibly upgrading your membrane to a higher volume one.

My water pressure is 70 PSI and a 150 GPD membrane produces very close to that in the summer. In the winter, output drops about to about 120 GPD.
 
@OP

If you're talking about add another membrane like the BRS water saver. Yes, you get more water production with a cost of burning out your membranes quicker, just make sure you have enough pressure to push and also it's a good idea to add in a flush kit as well.

I have it and I like it. Efficient? I don't know but one sure thing is you don't have to wait long for water.

Just remember to flush before/after use and replace sediment filters often, membrane should last a while.
 
How do you flush them? Bought a used unit but I replaced all filters and the membrane. It's a 75 gpd unit and I would say I'm pretty damn close to it's rateing. I guess hearing 75 gpd and then seeing it take an hour to make 3 gallons are 2 different things lol. It sounds like that's just what they make based off of what you are all saying.

My water pressure is around 55 psi all new membranes and I'm making close to what it's rated for. Not much I can do then unless I buy a bigger unit.
 
I ran a couple gallons of water through the sediment and carbon block before hooking it up to the ro membrane. But you said after each use? Should I be flushing the ro membrane?
 
How do you flush them? Bought a used unit but I replaced all filters and the membrane. It's a 75 gpd unit and I would say I'm pretty damn close to it's rateing. I guess hearing 75 gpd and then seeing it take an hour to make 3 gallons are 2 different things lol. It sounds like that's just what they make based off of what you are all saying.

My water pressure is around 55 psi all new membranes and I'm making close to what it's rated for. Not much I can do then unless I buy a bigger unit.

I don't think 55 psi is strong enough to handle 2 membranes.

Not all system have the flush valve installed, you could buy one and install if you like. I'm no expert regarding these RODI stuffs. Mine came with the flush thingy so I got into a habit of doing it. Some people says that the flush kit is a waste of money, some said it'll helps the membrane.
 
Titan Water sells a 150GPD membrane (TW30-1812-150) fro about $35. I've bought a couple over the past few years. The are 98% efficient and last well.

To flush the membrane, all you need to do is bypass the restrictor to run water over the membrane (not through) for 10 minutes or so. I check the efficiency of my membrane monthly. I usually see the output drop from 98% to 95-96%. That's time to flush. As long as it come back to 98% after flushing, it's good to go. If it doesn't come back, time for a new one. There are kits to make flushing an easy task. Check Ebay or your favorite LFS.
 
I just bought a 75 gpd from BRS for 35$ when this one needs replacing I will have to get the 150
 
A booster pump is one of my best purchases, gotta keep the water pressure where the unit recommends or its just a waste, Taunton water is like 40-45 psi, my unit ants 65-70 and it works great
 
Town water here is reading 70 ish on my rodi. No booster. 1 tds before my dual di stages too. Can be some big swings town to town.
 
Merrimack NH water pressure is 70-75 psi so my 75 gpd fills a 7 gallon container in 1-1/2 hour. Perfect for top off and 5 gallon water change weekly. But the TDS out of tap is 350 so have to remember to flush membrane really good before and after turning on DI so it last twice as long.
 
Filmtec membranes are factory spec'ed at 50 psi, and 77 degree water. If you have a different water pressure and/or temperature, you can use our calculator to fiure out how many gpd you should be getting.

Russ
 
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