Super slow RODI water production

Webbinator · Oct 15, 2019

Looking for some insight on my RODI system. Due to being on well water with high co2 I have to first run my water through the sediment and carbon block canisters and ro membrane then into a brute trash can for storage. That part goes fairly well and in what I consider a reasonable amount of time. I let that water gas off with a pump and large air stone for at least 48 hours. Next phase is pumping that water through my dual DI canisters with a pond pump sitting on the bottom of the brute can. This is where things drastically slow down. If I unhook the line going into the DI canisters I get a good strong stream of water shooting out. Once hooked back up and the water is passing through the canisters it slows to basically a quick drip. It can take up to 7 hours to make just 5 gallons of 0 tds water. Is that normal?

SeaDweller · Oct 15, 2019

maybe not enough pressure from the pump.

Seanislav · Oct 15, 2019

Webbinator said:
Looking for some insight on my RODI system. Due to being on well water with high co2 I have to first run my water through the sediment and carbon block canisters and ro membrane then into a brute trash can for storage. That part goes fairly well and in what I consider a reasonable amount of time. I let that water gas off with a pump and large air stone for at least 48 hours. Next phase is pumping that water through my dual DI canisters with a pond pump sitting on the bottom of the brute can. This is where things drastically slow down. If I unhook the line going into the DI canisters I get a good strong stream of water shooting out. Once hooked back up and the water is passing through the canisters it slows to basically a quick drip. It can take up to 7 hours to make just 5 gallons of 0 tds water. Is that normal?

I'm on a municipal water supply, and the water pressure going into my RO/DI system is 80psi. If the pump you're using is getting less than 50psi, you might need a stronger pump.

SlipperyWhipple · Oct 15, 2019

Webbinator said:
Looking for some insight on my RODI system. Due to being on well water with high co2 I have to first run my water through the sediment and carbon block canisters and ro membrane then into a brute trash can for storage. That part goes fairly well and in what I consider a reasonable amount of time. I let that water gas off with a pump and large air stone for at least 48 hours. Next phase is pumping that water through my dual DI canisters with a pond pump sitting on the bottom of the brute can. This is where things drastically slow down. If I unhook the line going into the DI canisters I get a good strong stream of water shooting out. Once hooked back up and the water is passing through the canisters it slows to basically a quick drip. It can take up to 7 hours to make just 5 gallons of 0 tds water. Is that normal?

Which setup did you buy? Was it the $60 one on Amazon?

Webbinator · Oct 16, 2019

SlipperyWhipple said:
Which setup did you buy? Was it the $60 one on Amazon?

Nope, it was originally a 5 stage setup from LiquaGen. Looks identical to any other quality RODI system. I ended up removing their DI canister and adding in the BRS 2 stage DI set. I do have to run a booster pump due to the lower well pressure. That only gets the water to the brute can though. Pumping that water through the DI canisters is where it drastically slows down. I get 0 tds water, it just takes a long time to do so. 7 hours for 5 gallons seems really excessive.

AdamB · Oct 16, 2019

Do you have a pressure gauge on your ro? Need to know your psi. If it is below 40 output will be slow ..I have a 4 stage spectra pure with di filter and pressure gauge with tds monitor. I also have a well with a whole house filter. When I first hooked up rodi my pressure was only 30 psi on gauge which did not hit the minimum of 40 psi that was recommended by spectra pure so I had 2 options. By a booster pump for rodi or switching out pressure switch on pressure tank to increase . I just bought a rodi booster pump and now and it’s boosted psi to almost 80 psi and I make 5 times the water amount or more in an hrs time.

Water Dog · Oct 16, 2019

What size pond pump are you using from the RO / degassing Brute trash can? May need a bigger pump or a pump that can handle pressure a little bit better.

SlipperyWhipple · Oct 16, 2019

Webbinator said:
Nope, it was originally a 5 stage setup from LiquaGen. Looks identical to any other quality RODI system. I ended up removing their DI canister and adding in the BRS 2 stage DI set. I do have to run a booster pump due to the lower well pressure. That only gets the water to the brute can though. Pumping that water through the DI canisters is where it drastically slows down. I get 0 tds water, it just takes a long time to do so. 7 hours for 5 gallons seems really excessive.

Yes it does. I asked that because I bought the Aquatic Life RO Buddy and for some reason the carbon filter clogged which was after the sediment filter and really slowed things down. I didn’t think it would be possible for the second filter in line to clog but it did and I ended up getting a replacement for it.

KStatefan · Oct 16, 2019

I would guess that the DI canisters are putting more back pressure on the pump than it is designed to have or there is a clog in the canister.

Webbinator · Oct 16, 2019

AdamB said:
Do you have a pressure gauge on your ro? Need to know your psi. If it is below 40 output will be slow ..I have a 4 stage spectra pure with di filter and pressure gauge with tds monitor. I also have a well with a whole house filter. When I first hooked up rodi my pressure was only 30 psi on gauge which did not hit the minimum of 40 psi that was recommended by spectra pure so I had 2 options. By a booster pump for rodi or switching out pressure switch on pressure tank to increase . I just bought a rodi booster pump and now and it’s boosted psi to almost 80 psi and I make 5 times the water amount or more in an hrs time.

Thanks for the input. Not sure if everyone is understanding my situation though. I basically have 3 steps in my system to achieve 0 tds water.

First step is pumping water from my well water source through first stages including RO membrane. I do have to use a booster pump to get it through efficiently. That water goes into the brute can for storage.

Second step is degassing CO2 off with an airstone for 48 hours. Those first 2 steps are not a problem and go as expected.

Third step is pumping water from the brute can through my dual DI canisters and into by 5 gallon storage containers. That third step is what doesn't seem right due to it taking 7 hours +/- to fill up one of those 5 gallon containers with 0 tds water.

I do have an extra RO booster pump that I had tried previously for the 3rd step. It's rated for 50psi and it REALLY moved the water through the dual DI canisters and I was afraid the water wasn't staying in there long enough to effectively strip off the final dissolved solids. I guess as long as my tds meter is reading 0 on the final output I should be OK? Is that safe to assume?

Webbinator · Oct 16, 2019

Water Dog said:
What size pond pump are you using from the RO / degassing Brute trash can? May need a bigger pump or a pump that can handle pressure a little bit better.

This one from Lowes:

https://www.lowes.com/pd/smartpond-300-GPH-Submersible-Fountain-Pump/1000597013

Water Dog · Oct 16, 2019

Webbinator said:
I do have an extra RO booster pump that I had tried previously for the 3rd step. It's rated for 50psi and it REALLY moved the water through the dual DI canisters and I was afraid the water wasn't staying in there long enough to effectively strip off the final dissolved solids. I guess as long as my tds meter is reading 0 on the final output I should be OK? Is that safe to assume?

Yes, if you’re getting 0 TDS from your RO Brute storage container through your dual DI canisters by using the booster pump, you should be good to go.

lapin · Oct 16, 2019

I would use the RO booster pump
0 tds is 0 tds at any flow rate

Water Dog · Oct 16, 2019

That pond you linked to is a fountain pump. It most likely is very poor at handling any head pressure. I’d stick with the spare booster pump.

Webbinator · Oct 16, 2019

Water Dog said:
That pond you linked to is a fountain pump. It most likely is very poor at handling any head pressure. I’d stick with the spare booster pump.

Perfect, thanks everyone for the great input and advice!

AdamB · Oct 16, 2019

Webbinator said:
Thanks for the input. Not sure if everyone is understanding my situation though. I basically have 3 steps in my system to achieve 0 tds water.

First step is pumping water from my well water source through first stages including RO membrane. I do have to use a booster pump to get it through efficiently. That water goes into the brute can for storage.

Second step is degassing CO2 off with an airstone for 48 hours. Those first 2 steps are not a problem and go as expected.

Third step is pumping water from the brute can through my dual DI canisters and into by 5 gallon storage containers. That third step is what doesn't seem right due to it taking 7 hours +/- to fill up one of those 5 gallon containers with 0 tds water.

I do have an extra RO booster pump that I had tried previously for the 3rd step. It's rated for 50psi and it REALLY moved the water through the dual DI canisters and I was afraid the water wasn't staying in there long enough to effectively strip off the final dissolved solids. I guess as long as my tds meter is reading 0 on the final output I should be OK? Is that safe to assume?

Understand your situation now. My brain has finally woke up this morning ! If your tds is 0 with booster you should be good then.

Breadman03 · Oct 16, 2019

You essentially have 2 systems to consider. You have an RO system to a degassing vat. You then have the second system to make DI water. I would plumb in a RO booster pump to feed the DI. Pond pumps aren't generally made for much head pressure, which includes blowing through a coffee straw.

pdxmonkeyboy · Oct 16, 2019

I would degass, then use one pump to push it through your whole system. I dont see a reason to split up the process. But there may be details i am missing.

SeaDweller · Oct 16, 2019

I understand your problem, but as been pointed out by others as well, it's possible the pump you're using to push the degassed water thru the canisters might not providing enough pressure to push it thru the canisters. You can try this:

DIY CO2 Degassing Chamber for RO/DI

Well, I learned the hard way that the water coming out of my well has a high CO2 content. I burned through a pound of DI resin and only got 40 gallons out of it.... To keep this from happening again, I could either buy lots of RO/DI water or remove the CO2 from the RO water before I pass it...

www.reef2reef.com