RO topoff & TDS creep

[mark]

Yes it does start and stop hence the FAIRLY constant comment but my TDS are low. RO/DI been up for quite awhile with the same filters and believe that's the reason for the 7ppm as up to a few months ago a lower TDS was more common.

As for the RC idea seems complicated to me just to add some water. Had at one time planned similiar that would just fill a large vessel every few days (by timer and float, or just manually opening a valve but with the float in the holding vessel in case I forgot to turn off) then gravity feed sump through the float valve thats in the sump. Until that was setup I put the ro/di direct to the float. Ended up it's working fine as is so jut left as is.

Getting back to the range I have (1/4" variance) perhaps thats the reason for my low TDS as opposed to waiting (time between cycles) to drop 2 inches.

picture of the valve I'm using in this thread http://216.187.96.54/vbulletin/showt...ighlight=float

[Dave C]

Originally Posted by mark

Getting back to the range I have (1/4" variance) perhaps thats the reason for my low TDS as opposed to waiting (time between cycles) to drop 2 inches.

Could be. I doubt my water level fluctuates by 1/4"... much less then that. I'm going to leave my float/solenoid on for the day and test the tds of the water entering the sump throughout the day and see what it measures. Could be making something out of nothing. And right now it's only servicing about 100g of water in my 65g tank/35g sump system. Once I add a 225g tank with sump it might really not be an issue as it will probably be running much more often & for a longer period of time. That's especially true since I'll have a high/low float on the 225g tank so the water will drop 1 or 2" before the RO will kick in and then it will run for awhile to top up.

[littlesilvermax]

I have an RO storage tank that holds 14 gallons of water. The valve the automatically turns on the RO has a pressure switch that turns it on at 60% of line pressure, so after maybe 4 or 5 gallons is used it will turn on.

My tuperware container is there to first aerate my top-off water, and provide a clean environment for my float valve to work and not get plugged (seeing it is at up to 60 psi). From the container I have aline that feeds the main tank via another float valve. This valve can get much more crap in it and still work becasue it is at only about 6 feet of pressure or 2.5 psi.

[Railskinner]

Pictures of top up systems that people use would be a gr8 addition to the thread.
I have a ro/di unit hooked up to a 10 gallon container operated with a humidfier float valve ( bought at HD). Thats as far as i got so far, still taking water from container by hand (syphon)to top up sump.I loose about 1 gallon a day due to evaporation.Ro/di unit starts and doesn't run long replaces what i use, I was thinking of putting another float in sump, hasitante as thinking this would just be a trickle system then from ro/di to 10 gal.container to sump.Might as well went straight from ro/di unit to float valve in sump then.How does one rig container to drop 3 to 4 gallons then kick in ro./di unit.So this then would cause my ro/di unit to kick in about every 4 days creating new water.

[Dave C]

I've been testing the water from my RO unit throughout the day for a week or so now. I do it when I notice that my topoff unit kicks in. When it does kick in it puts water into the sump for about 5 seconds and then shuts off. The TDS of the water coming into the tank ranges from 65 to 150ppm. Not good. If it were to run for a good minute or two it would be great as after running for 15 seconds it gets back down to 0ppm. But the way it's going right now it's adding crappy water to my sump.

[Railskinner]

I also have the same problem with the first water at reading being around 50's. I think this is the water that sits in the RO unit for awhile. Then the water levels out with a lower reading when ran for a minute.This is what goes into my container, test the water in my container and it reads 5ppm. This is the water that goes into sump.I can live with that.

[Dave C]

I agree. But when my float switch drops & the RO starts it doesn't run for a minute. It stops well before that. So it never gets to the point where the water tds levels out with a lower reading. It also is supposed to deplete your DI resin much faster to be intermittently starting & stopping your RO unit. Much better to run it for 5 gallons & stop it.