RO/DI Water Changes

[dankolle]

I finally have a 6 stage RO/DI filter coming tomorrow!!! I want to plan my water changes so I can get rid of the city tap water that is currently populating my aquarium. How aggressively should I change over my water? I usually do about 8 gallons a week, but I am having some algae issues (green slime, diatoms, and some other nasty brown stuff) so I want to get clear water in there ASAP!

 

[Bifferwine]

20% once a week or twice a week is fine. The algae issues are not going to be resolved overnight, unfortunately. It will take a while, but they should definitely get better now that you are using better water. Congrats on the new unit!

 

[Ogaawd]

awesome! let it run off at least 5 gallons to purge the unit

 

[dankolle]

It arrived a day early! :bounce:Their directions said to run it for 15 - 30 minutes so I errored on the size of crazy and did 35 : )

It is a 6 stage 150GPD system. I had a question about the flow...It seems the "clean" water is coming out just faster than a steady drip, kind of a stream, but no where near the speed the discharge water is.

I have it hooked directly to the water tank feed line and the well turns on when it reaches about 45 PSI and cranks it back to 60. I know it's like 5:1 bad / good but is this normal operation? For the RO/DI not my well :D

 

[bjohanson1234]

The dirtier the water going into the unit, the more waste water will be produced. Since you are on a well, you might have high disolved solids. What is your TDS reading before and after the RO unit?

 

[dankolle]

Not sure my TDS meter is still in Hong Kong : ) Should have it next week...I know we have really hard water but never had it tested before

 

[tankedchemist]

depending on your unit, the waste water will be 3-5 times faster than the good water. My RODI unit has a flow restrictor so the ratio is 3:1.

BTW, read your RODI unit manual.. you can blow the seals if you've got the incoming pressure too high. I did it once just on regular tap pressure, so be careful :)

 

[dankolle]

It took me about 4 hours to make 4 gallons of water...so it is running really slow. It should make 6.25 gallons per hour if it is a 150GPD shouldn't it?

I checked on the pressure and it says at least 35 but no more than 60 so I am right in the "optimal" range I would think. I think I will learn more once I get my TDS meter

 

[bjohanson1234]

How cold is the water going through it? I believe that the colder the water, the slower the operation of the RO

 

[dankolle]

Very cold...I'm in northern michigan so we are looking around 38 - 42 degrees probably. The unit says 33 is the absolute lowest it can operate...which is a "no duh" :)

 

[bjohanson1234]

Would it be possible to put the water in a holding tank that sits at room temp until you run the RO unit?

 

[dankolle]

I have it coming off my holding tank but I am not sure how long the water sits in there if it has a chance to warm up that much. I guess I'm not worried about the time it takes just that the unit is working properly...

 

[Ogaawd]

Id be more concerned about how much water your well makes a day

 

[dankolle]

When I ran it last night I made 4 gallons of water in 4 hours. I put the discharge water into my washing machine that is a "Super Capacity" and I think it is 3.5 cu ft. It fills it 1/2 full for the 4 gallons.

I did a little math and came up with this:

3.5 cu ft can hold 26.18 gallons of water.

26.18 / 2 = 13.09

Then taking a 3:1 ratio of bad / good from 4 gallons of RO water it should produce about 12 gallons of bad. So my well isn't running that much it is just producing really slow!

 

[dartmyth]

the first few times i made water with mine it seemed to take forever. But after a while it seemed to get faster just think it takes a while to break in.

 

[dankolle]

I better keep my timer set for an hour instead of 4 then hu? : )

 

[Ogaawd]

so will you be able to use the waste water for dishes? that would be very eco

 

[dartmyth]

could use the waste water to flush the toliet

 

[dankolle]

I am using it to full the washing machine...it makes laundry faster because the tub is already full so you can dunk your cloths and it starts washing right away w/o filling time!

I have about 65 gallons of water in my system and I have been doing small water changes of about 3-4 gallons per day now and I can already tell my glass isn't getting the normal "daily" algae buildup it usually gets. I'm using RO water for fresh top off too and my sand bed would usually be covered and it is starting to clear up!

I can't wait to see what happens when the tank is 100% RO water!!