RO/DI Output Need a little help!

[scuba_steve]

Could someone please explain to me how their RO/DI Unit works? I bought one and all it does is drip out. At this rate, it will take a day to fill up a 5 gallon bucket. I did check the TDS and it reads "0". Is the reserve tank supposed to fill up first before the flow increases? My unit is supposed to be 100gpd. So if my calculations are correct, with 24 hrs in a day, the unit should produce 4 gallons per hour or 1 gal every 15 min, approx. Could someone please help me out?

 

[scuba_steve]

Would using just RO water speed up the process? If so, how much worse off would I be compared to RODI water?

 

[Mikef1]

If you hgave RO/DI use the DI. You will see an increase in pressure once the tank is filled, so let the tank completely fill. Also if this is a new unit you will want to waste the first 10-15 gal and dont run the di durring this period it will just wear it out faster. When doing this you are breaking the RO membrane in. Does your unit have a pressure guage?

 

[Mikef1]

By the way Steve Welcome to Reefs.Org!!

 

[scuba_steve]

thanks

It took me 7 min to fill one cup of water. So rough calculations show that production is no better than 25 gpd. It is supposed to be closer to 100gpd.

 

[Mikef1]

This can also be caused by low water pressure comming off your water line

 

[Mikef1]

Steve, is this unit brand new? You need to let it break in and then it should start to produce more water give it 20 gal or so and then see how much it produces. If it is new you probably still have air in the unit, which you can probably hear.

 

[Aquadude]

If your RO unti came with a water tank with a air gauge connection (looks like the fitting where you put air in a tire) you can check your household water PSI. Connect the output of your prefilters (not the RO filter) to the water tank water connection (at the top) and allow the tank to fill. Water flow sound will stop when tank is full. Check your water pressure with a tire pressure gauge. You will need at least 40 PSI for good product to waste water ratio. The higher this pressure the better (within limits of course). My house pressure is 66 PSI and I get good output with my 100gpd filter. If you have less pressure than 40psi this then you will need something called a booster pump to bring the pressure up for the RO membrane or you will be wasting a lot of water and not getting enough product water fast enough. If your water costs are high it may even be worth it to buy the pump even if you don't need it.

 

[WannaBeReefer]

The temperature of the water going in has alot to do with production as well. The colder it is the slower it drips. I had to buy a pump to up my pressure from 40PSI to about 80 now. Still no go, water was to cold, so now I have a 5 gallon pal with a 300 watt heater in it cranked up. I bought 50 feet of extra tube and used it between the faucet and the first filter. The extra 50 feet sits in the bucket and heats the water up before it enters the unit. Works much much better now.

 

[scuba_steve]

I checked the temp of my water and it is 51 degrees. I have plenty of psi in my waterlines. I guess I'll just let it run and see what happens. I just didn't expect such a slow initial rate. It will take me almost 3 hours to get 2 gallons.

 

[WannaBeReefer]

My temp is around the same, it wont get better until you get the temp closer to 70. I had a long discussion about this with the guys at Kent Marine. I went from 15 to 1 to about 4 to 1 with the temp. Pump helps but really kicks in when the water is warmer.

Welcome to my hell.

 

[Unresistible Blue]

I checked the temp of my water and it is 51 degrees. I have plenty of psi in my waterlines. I guess I'll just let it run and see what happens. I just didn't expect such a slow initial rate. It will take me almost 3 hours to get 2 gallons.

Steve - did you get things squared away?

Blue

 

[scuba_steve]

pretty much. I guess I should have know that even though the filter is rated at a certain gph, it probably will not produce at that rate. The unit is providing 2 TDS water and I am stockpiling it, so I'd say it is working.

thanks

 

[Unresistible Blue]

If you want to increase your production think about your line pressure and water temp first.

Blue

 

[Reefman150]

You may also want to check to see if there is a check valve in the output fitting on the membrane housing. If you are not using the RO for drinking water, you may want to remove this tiny check valve. I had this problem for over a month before finding out there was one there. I also warm my water first using 50' of tubing in a bucket of hot water. The check valve was by far my biggest problem though when I had low to no output.