Max TDS?

[Don Trinko]

Our water is softened by the village. It's TDS is abought 700. I have been mixing with ro. There may come a time when I can not affort to use the ro. I realise that I would have to gradual change from ro/tap to straight tap water.
Would discus do OK in 700 TDS? Thanks; Don T.

[Mr Wild]

Blimey! Liquid rock!

[wgtaylor]

Hey Don, I don't believe they would have a problem at 700 for growout but all depends what is in the water that is driving up the tds.
Have you thought about running multiple canisters in series, I read you can get down to 10 - 15 % waste.
Bill

[Don Trinko]

My son inlaw is in the water buisiness. I will ask him how to minmise the waste. He say's that typicaly I will have 2 to 4 g waste for each ro gallon. It's not a problem yet b ut it could be 10 or so years down the road. Don T.

[Chad Hughes]

Don,

Have you considered collecting the waste water? I collect all of my RO waste water and use it for yard watering. I have grass and a lot of fruit trees. I make 500 gallons of waste water every week. I use it to water my whole property twice a week. By using the waste water, I am actually cutting back in my usage. Just something to think about.

Best wishes!

[utiliy]

my tds out of the tap is over 500...i use tap for 2 tanks, a 75g and a 125g.
i have a breeder tank (29g) i use ro water-which i am new at...to think the ro brings it down to about 13-15 tds, seems kind of not fair to the other 2 tanks. i add a cup or 2 of tap and some buffer to bring it up.
i have no probs with the tap water-its free here-and the discus i have in it are growing kind of fast. in the long run-well-we will have to see.

[Don Trinko]

My one ro is on the 2nd floor so using waste water would be difficult. The other is in the basment so i could do it there.
I have been using 50ro/50tap for all fish . I could also use 100%tap for all but discus tanks but the discus are the big user because they get more wc than the other tanks. Thanks; Don T.

[wgtaylor]

Don, don't know if you use a booster pump but that would increase the capture rate.
I found the article on using up to 6 membranes in series to achieve a theoretical capture rate of about 84%.
http://www.remco.com/ro_quest.htm

Bill

[Chad Hughes]

Don, don't know if you use a booster pump but that would increase the capture rate.
I found the article on using up to 6 membranes in series to achieve a theoretical capture rate of about 84%.
http://www.remco.com/ro_quest.htm

Bill

Bill,

That is VERY interesting. Currently I operate two membranes on my RO syste but the are in parallel with each other. I am now wondering if I should switch the configuration and see what happens. What do you think?

Best wishes!

[wgtaylor]

Bill,

That is VERY interesting. Currently I operate two membranes on my RO syste but the are in parallel with each other. I am now wondering if I should switch the configuration and see what happens. What do you think?

Best wishes!
I think in parallel you get 20% permeate from each membrane. More product water but no net gain saving water, I think. Running in series is like reusing your waste to feed back through your ro system again instead of out the drain. Should work.
If you come up with a cost effective solution it might be worth posting a complete and simple diagram for others to use. There are a lot of water challenged discus keepers that could benefit.
Bill

[Chad Hughes]

I think in parallel you get 20% permeate from each membrane. More product water but no net gain saving water, I think. Running in series is like reusing your waste to feed back through your ro system again instead of out the drain. Should work.
If you come up with a cost effective solution it might be worth posting a complete and simple diagram for others to use. There are a lot of water challenged discus keepers that could benefit.
Bill

I'm one of the challenged Bill. LOL! Righ tnow I just collest all the waste and use it elsewhere. I'll give it a go and let you know!

Best wishes!

[erikc]

Don, don't know if you use a booster pump but that would increase the capture rate.
I found the article on using up to 6 membranes in series to achieve a theoretical capture rate of about 84%.
http://www.remco.com/ro_quest.htm

Bill

Good comment Bill.

In Europe this technique is used (not widely) but I am seriously thinking about it myself. I have only a four stage RO unit but the pressures losses are such that there is a lot of waste. This system does make sense and is effective(water is becoming an expensive comodity). Some suppliers boast a capture rate of a 100% but I should be wary of anyone who advertises this without using an industrial setup.
A capture rate of 85-90% is probably what you would get with such a system. This is definetely a good answer to the problem of RO waste water.

[Mr Wild]

You will just have to move over here John my natural TDS is 12ppm between us we would have in conquered!