R/o Query

[elmo666]

Hi. I use R/O on my discus tank. I noticed a pool of water under the sink so investigated its source, as I also have a 3 stage hma filter under there. I could hear a very slow hiss from the mains supply, and discovered for the first time that the waste water side is constantly running on the R/O, as,I only tend to turn off the tap on the end of the line to the bucket, and not the inline tap I put in after the self cutting valve. So I googled wether or not I should leave it running on the waste side but couldn't get an answer. What I did find lots of info tho was on back flushing the membrane at regular intervals. Never heard of this tbh. Does anyone with an R/O unit do this, and if so could you advise me on how to go about it pls, if indeed,it is required. Thanks. P.S. My R/O tds is 4-5 whilst my tap water is 135-150. I use 50 ltrs twice weekly, disposing of the first 5ltrs or so each time.

 

[techen]

Uh.... I wouldn't be running it all the time, You are pretty much reducing the lifespan of the membrane,. You need a cut off valve going into the RO unit to stop water traveling through it and only push water through it when you are using it.
 
Mines attaches to my hose outside, Plug it in and use it when I need to and then store it away. However, I have discus and I don't use RO water myself but since my waters TDS is 036 am not fussed at all

 

[DrRob]

Units will stop if there is back pressure, the ones with ball valves going into a tank work this way, a bit like the toilet cisterns, but they also tend to have a valve that closes off the feed line when the exit line is blocked to protect the membrane from high pressures (they're called things like auto shut off pressure valves).
 
As for flushing the membrane, many kits come with a flush valve. Basically it runs filtered water over the membrane straight to waste. It's regarded as good practice for keeping the membranes functioning for longer. It costs a little extra water and I've heard many answers about what people do. Given half a chance I run the flush for 5 minutes before I start using the RO unit and then about half an hour after stopping to make sure that the membrane stays in good condition and I'm still on my first membrane after a number of years of mild usage.

 

[elmo666]

Thanks for the reply's. I think I mightn't have been clear Mr overlord, sorry. Its only the waste I can hear,trickling when the product water is shut off on the valve on the end of that pipe. I'll now start shutting off the valve before the unit as well