how long to make 5 gals of RO/DI water?...

[thebigblue]

how long does it take you to make 5 gallons of water with your RO/DI units?...

it takes me about 8 hours on my Kent 35 gpd unit...

my buddies filter seems to make it ALOT faster...??...like 5 gals in an hour...??

thoughts?...

someones is hooked up wrong?...

thanks

brad

[Claude Poole]

My 50GPD unit takes about 20 minutes per gallon. I think something is wrong with yours.

[L and L]

It's probably the pressure of your line. Just fyi.... but, when they say Gallons per Day.... they are talking in 24 hours.

I have an Aquatic Reef Home Drinking System (5 stage RO) and I added DI to it (5 micron right now as bought...but, I bought 1 micron filters for my 6 months change) .....and it's a 50 GPD also.

If you take 50 and divide by 24 hours... you get 2.08 gallons per hour.... or around 1 gallon per 30 minutes.

This is all based on the maximum pressure it can handle ( i think it's around 120 psi).

You're 35 GPD should give you 1.5 gallons per hour (at optimum pressure). Since you get 5 gallons in 8 hours and that is 0.625 gallons per hour..... and assuming 120 psi is the standard pressure they calculate the 35 gpd .....
The pressure of your line would be around 50 psi.

Does your buddy have the same 35 gpd Kent system?

Do you have a Handheld TDS (total dissolved solids) Meter? What's the reading of your water?

If there isn't something wrong with your setup.... and you want to get RO/DI water faster ....then you may need to buy a booster pump to pressurize your water.

If you don't want to deal w/ buying yet....more stuff =) pumps etc... Then buy a Rubbermaid garbage can and find a storing place and fill it up at night (AND make sure you turn it off in the morning ...hehe.... I have overflowed my 75g rubbermaid more times than I can tell =) I could buy a flow control valve / float valve...but, I wouldn't have anything to laugh about then =)

I would call ARS and speak to Bryan Crenshaw and he'll give you great advice. www.aquaticreefsystems.com

You could also call your water utility company and ask them what kind of pressure you should be getting at your home.

[L and L]

oh yeah... here is my system:

[tendar]

My aquatic reef systems 50 gpd ro/di takes 80 minutes to make 5 gallons with a reading of 0 ppm at 45psi.

[Ltspd]

RO/DI units need 2 things to work well.

1) water pressure

2) Temp.

Water pressure need to be above 60 PSI (It may only be 45) and the water temp coming into the unit needs to be 70+ degrees. If the water pressure is too low it can pass the membranes very well and if the water temp is too cold it cause the same effect.

Solutions:

1) Increase water pressure by either increasing it at the sorce or pressure regulator in the house or a water pressure pump commonly sold by RO/DI manf.

2) Several options here IMO. a) Thermostatic mixing valve b)manual mixing of hot and cold water sources c) creating a heat up unit where the feed tubing is coiled up in a heated water tank d) a heated tank that feeds the unit itself.

[Claude Poole]

Well this may be a double post. I was in the middle of typing a reply when it went Poof!

As I was saying earlier my 50GPD Dow RO/DI unit with Kent membranes and filters produces 1 gallon of RO water in 20 minutes. It took quite a bit of tweaking to get it to work right with my set up.
We have a well and the pressure at the unit was only 35 PSI. I installed a booster pump and now the pressure is around 80 PSI. The water temperature is that of underground water 50-55 degrees F.

Should you install a booster pump you will have to be careful that it is compatible with your stop valve otherwise when the unit stops making water the pump may continue to run. The pump manufacturer was telling me not to worry that the pump was on standby or something like that. I didn't like the idea particularly since the pump was getting hot to the touch, plus the waste of electricity. Finally after a lot of back and forth the supplier I bought it from took the unit back and removed the 4 way stop valve replacing it with a regular valve. They had to do quite a bit of testing of different valves and finally ended up ordering an American made "Hydronautic" valve which works more accurately with the pressure switch. They're also much more expensive. The pressure switch before the storage tank was also changed from a 60PSI to a 40PSI. I have a 3 gallon storage tank before the DI to feed water to my kitchen sink. I guess the system was too complicated for the 4 way switch to work with the pressure switch on the tank. Anyway, it works now, at least pressure wise.

I still have a problem and may be some of you can help me with that:
I do not seem to be able to draw more than 2 gallons of DI water at a time without the water level in the DI cartridge going down. Then I have to wait for the tank to refill before I can draw water again. It's a real pain in the ****. Custom Aquatic from whom I bought the unit do not seem to be able to figure that one out. Any ideas anybody?

[thebigblue]

thanks for the great replies...

i have a kent 35 gpd RO/DI unit...i have the cold water line split coming into my washing machine, so maybe im losing some pressure there?...

as someone said, i guess im getting about 50 psi, and im sure the water temp is pretty cold...i am gonna try and call my water company and see if they can tell me the pressure....

my buddies unit is actually the kent 65 gpd model, so i know he should get better results but i didnt realize it would be that drastic...he has his hooked up to a laundry sink faucet where he can control the volume of water goin thru...and maybe he can even use warmer water?...

i may try hooking mine up to my laundry tub sink?...how do you guys have yours hooked up?...to a sink?...

i dont think a booster pump is something i would wanna try, even if i could get 5 gals in three or four hours i would be happy!...

thanks

brad

[Claude Poole]

Brad:

Go to Home Depot and get a guage for $10 or so. Install it just before the membrane. You need to know what your pressure is. If your pressure is 50PSI as it enters the house you have a lot less by the time it travels to whereever your RO is located. In my case I lost 10lbs from well tank to RO.

If your pressure is low you need a booster pump for the membrane to work right. At low pressures the membrane lets a lot of stuff through.

You might want to call Kent Marine for input since it's their unit. 770-966-5200 X-13 ask for John. He was very helpful to me.

Claude

[Claude Poole]

Paul:

It was my understanding from talking to John that low temperatures affect the yield but not the quality of the water. I think they have all the calculations regarding temp and pressure on their web site. At least they did a couple years ago.

I believe that at 50degress the yield is halved.

Claude

[Ltspd]

That is correct, only the yeild is comprimised. I would guess that it may actually produce a lower TDS because less is allowed to pass the membranes.

[Claude Poole]

Brad:

my memory was faulty. You will find calculation table on SpectraPure website not Kent's

http://www.spectrapure.com go to FAQ. Question next to last will help you.

L & L:

For some reason your picture was not available to me yesterday but came up to-day. I see you have a water storage tank like mine. Does the water in your DI go down as you draw water from the tank? Thanks


Claude