It's a false reading. R/O has no buffering capacity, so there's no real pH. You're essentially measuring noise.
Willie
My ro is ph6. I adjust water gh and KH to around 4. Then if I put an air stone in or sponge filter the ph will hit 7.8 in just over an hour.
This is not good when it comes to water changes.
What is going on?
It's a false reading. R/O has no buffering capacity, so there's no real pH. You're essentially measuring noise.
Willie
At my age, everything is irritating.
Hi and welcome Chris . You propably have a big pH swing due to dissolved gasses in your tap water .
You will need to consider aging your water with agitation for at least a couple of hours prior WCs .
My tap does the same kind of swing but not with that intensity .It comes out of tap 7.5 and it settles down on 8.2 after aging .
Thanks for your replies. I’m glad I joined up.
I will be trying that now. I will buy a 7 day timer switch for my air pump to run before my water changes.
So ph8.2 is ok for discus?
Note that Chris is referring to R/O water, not tap.
Willie
At my age, everything is irritating.
How old is the RO unit?...you may need new diaphragm and carbon/sediment filters
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It is my understanding that you may still need to age RO water. I had to.
Pat
Your discus are talking to you....are you listening
My well water is loaded with dissolved CO2, which goes right through an RO membrane. So the water comes out of the filter very acidic. By the time the barrel is full the water is partly aged, but still needs a few more hours before the pH matches the tank pH.
My ro unit is 2 months old.
Put a strong pump with sponge or better yet floss upwards to agitate the water in the aging barrel making a fountain while RO is filling , and it will be outgassed and setteled before the RO unit is done .
Most water will have to aged, including RO. Water under pressure contains compressed Co2. Co2 expands faster than o2, which is why you see the bubbles. Once the bubbles are gone, your water should be ready to use. Just be careful to do regular water changes because RO has no buffering ability and you can easily experience a ph crash in a very short time...
Unless you are breeding your discus, RO isn't really needed. Your goal is consistent ph, not low or high ph...
Great info guys.
My water sits in a water butt, in the shed for 2-3 days before I need it. Do you think I could use a solar powered air pump running for those 2-3 days? ( no power in shed )
Also, do I need to raise gh and KH before agitation?