Help for beginner - Is RO water waste good for discus ?

[Newdiscuslover]

Hi guys !
After 15 years in the reef hobby, my wife wants to start a discus tank.
I own 4 reef tanks and have enough knowledge to run my tanks and keep in the hobby.
When my wife asked to me to start a discus tank, I got afraid, it’s a whole new world for us.
I already talked with some LFS owners, read forums and watched tons of videos but as in the reef hobby, I found many different information.
But one information I got from my LFS made me more confused.
The owner told me discus love RO water waste ! But the waste must have no signs of chlorine. And he told me I can use the RO waste.
I have 200 gallons of RO water waste weekly.
If I can use the waste, my pocket will be happy !
Does anyone here already use RO water waste to keep discus ?
What is the best water parameter to keep Discus healthy ?
Another question is about sump. Some people and LFS run tanks with sump but what kind of sump is recommended ? I mean, how many chambers, ceramic bioballs for bacteria, foam ?
Hope you guys can help me in my new challange.

[DonMD]

Discus like lots of water changes with stable water that matches their tank water. Same temperature, same pH, same TDS. It really doesn't matter what the pH is, as long as the water you use to change is the same as the water they're in. I never bother checking pH. As for using R/O waste, that water is high in TDS. Discus can do fine in it as long as it's not excessive, imo. I used R/O for my breeding tanks, and just city water for my display tanks. What is the TDS reading of your R/O waste?

[White Worm]

Just the opposite for RO waste water. You are better off using a combination of tap/RO for keeping discus. A sump can be just a simple tank divided with foam, filter floss, anything to collect beneficial bacteria and a pump for return. The mineral concentration of waste water will be somewhat higher than the source.

[pitdogg2]

Go with the K.I.S.S. principles. I kept Discus for years with just aged tap water ph between 7.6-8.2. They did fine laid eggs had wigglers and free swimmers all the time. My water was not soft by any means but it was very stable.
Lots of big water changes and good food you will be rewarded

[Newdiscuslover]

Hi ! Thanks for reply. My RO waste TDS is around 202. Is too high ? Yesterday I ordered chlorine test strips to check my RO waste. If I find chlorine in my RO waste, what kind of product do you recommend to use ? Seachem Prime ?

[Newdiscuslover]

Thanks for the reply. I read about mix RO and tap water but what is your sugestion ? 70-30 ?

[Newdiscuslover]

Thanks for the reply. Do you add somenthing in your water, like Seachem Prime or Seachem Discus Buffer ? And how about bacteria ? Do you add live bacteria to start the cycle in a new tank ?

[pitdogg2]

Stay away from Discus buffer. I used Seachem safe it is powdered form of prime and much more economical with the amount of water changes.

[DonMD]

Prime is a good product for ammonia. 202 is not too high TDS for discus.

[Newdiscuslover]

Thanks guys. In reef tanks I need to add bacteria, specially when cycling a new tank. Is the same for discus new tank ?

[Jbarnes]

Great topic as I'm in the same exact situation. Like everything in this hobby I got mixed messages on using RO waste. My RO waste is only 87 TDS. I was warned that phosphate etc. would be much higher. I have not tested PO yet.

[Newdiscuslover]

Thanks for the input and the great idea. I just did PO test and it was zero with the cheap API test. But I never had PO issues in my reef tanks so I believe the test results are trustable. Hope your PO test result be the same. Now I’m just concerned about chlorine test. Tuesday I’ll get the test strips and I’ll do the test.

[Hart24601]

It just depends on your source water. Here in the middle of agriculture, Iowa, our water is pretty poor - like nitrates above the legal limit and very high phosphates. I use RO/DI in my discus tank instead of tap water, let alone use the RO waste! Chlorine should be removed in a proper RO system before the membrane so no worries there or you have pretty much burned out the RO membrane already. That is the main reason for carbon blocks before the RO membrane. If you test positive for chlorine replace those carbon filters right away as they will very quickly ruin the membrane.

If your tap water isn't horrible then the RO waste water, especially if using something like a 4:1 rejection, will not be too bad but be sure to test it. I use my RO waste water in a planted tank as the TDS isn't bad and there are not very many salts, and the plants enjoy the constant phosphate and nitrate.

[White Worm]

Thanks for the reply. I read about mix RO and tap water but what is your sugestion ? 70-30 ?

Yes, but I used something like that for breeding and then returned to straight tap once fry hatched.

[ssevasta]

Thanks guys. In reef tanks I need to add bacteria, specially when cycling a new tank. Is the same for discus new tank ?

You don’t need to add bacteria, all you need to do is add pure ammonia to the tank to do a fishless cycle. I ordered the ammonia on amazon to make sure it didn’t have any other chemicals mixed in. They sell bottles that are meant to be used for cycling aquariums. It’ll take a few weeks to cycle your tank but this way you can be absolutely sure that your tank is clear of any pathogens when you add the fish. You can find threads in the beginners section on the forum for additional instructions and information on doing a fishless cycle.