RO/Di Water Question

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Aquarium Advice Apprentice
Sep 16, 2011
Harveys Lake, Pa.
I have a Ro/di water filter purchased and on its way to me..Im Realizing illl have to correct the waters Ph since my well water has a low Ph at 5.7.Anything else i need to know?? Thanks
Any RO water needs to be buffered. RO/DI water should have a TDS of 0, this means it doesn't have ANYTHING in it, it won't even conduct electricity. What are you using the water for?
When you add the salt mix it will buffer it. After you make a batch of it then check your PH. It should be OK but if not they make a buffer for it.
At the beginning I would just add the water and then check your PH of the tank water. If you see it falling then maybe add the buffer. I think you should be OK though. Remember the SW already in the tank will be buffered because of the salt mix. Add some FW and check your PH about 6 or 8 hours later.
How often & how much volume do you top up?

In my case, it's such a small percentage of the overall volume that the buffering capacity of the water left in the tank keeps it stable at 8.3.
You top off as needed, to keep the tank full from evaporation.

It doesn't matter what the source water is, hard or soft after RO/DI it will be as soft as possible, no matter where it starts. As stated already, a proper salt mix will adjust pH/KH, Ca, Mg, etc.

You do not need to alter top off water. It replaces evaporation which is only water, nothing else leaves. So it should be nothing but water going back in.
If I could jump in here and ask for a clarification on something I have suspected for a while but never heard addressed. If in fact the RO/DI removes everything, is there a need to condition the water for chlorine before mixing? I mean 0 is 0 right? I have continued to treat my RO/DI water but I think it is a waste.
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