pH Question

[PAR23]

The tap water in my area has a pH of 7.0-7.5 and TDS of 50. The pH increased to 8.0-8.5 after letting the water sit in a holding tank for 72hrs but without a pump or air stone. My questions are:

1 If I aerate the water, will the pH reach 8.0-8.5 within 24hrs?
2 Should I use "aged water" for water changes?
3 Is it necessary to modify the pH and how to do it since discus thrive in acidic water?

Thanks in advance:confused:

[Eddie Wells]

1. It really should.
2. Yes if your ph changes that much
3. Not if your going to get 2 to 31/2" fish to grow out


Eddie Wells

[waj8]

What the units of that TDS reading?

[PAR23]

What the units of that TDS reading?

The TDS is 50 ppm.

[Eddie]

1 If I aerate the water, will the pH reach 8.0-8.5 within 24hrs?
It probably will, you will need to test it.

2 Should I use "aged water" for water changes?
Its always best and as mentioned, with a ph change that great, its a must. Your water has high co2 gas and once its gassed off, the PH climbs. I would like to know what your kH is.

3 Is it necessary to modify the pH and how to do it since discus thrive in acidic water?
Not necessary at all, your water is very soft I assume, with a TDS of 50. Again, would like to know what your kH is and also your gH.

[waj8]

I could be wrong but a TDS of only 50 ppm your water would be considered soft and could not possibly have a high KH even if all the hardness was due to carbonate. So, I am at a loss to explain the high pH readings. I am thinking either the TDS is wrong or the pH is wrong. Anyway, something seems fishy to me.

[Eddie]

I could be wrong but a TDS of only 50 ppm your water would be considered soft and could not possibly have a high KH even if all the hardness was due to carbonate. So, I am at a loss to explain the high pH readings. I am thinking either the TDS is wrong or the pH is wrong. Anyway, something seems fishy to me.


Yeah, that was something that had me wondering as well. I asked to know the kH and gH to see if this jives. TDS of 50 ppm is like RO water which would be very low in both kH and gH and PH. :o

[PAR23]

Yeah, that was something that had me wondering as well. I asked to know the kH and gH to see if this jives. TDS of 50 ppm is like RO water which would be very low in both kH and gH and PH. :o


I could be wrong but a TDS of only 50 ppm your water would be considered soft and could not possibly have a high KH even if all the hardness was due to carbonate. So, I am at a loss to explain the high pH readings. I am thinking either the TDS is wrong or the pH is wrong. Anyway, something seems fishy to me.

Thanks Eddie and waj8 for your reponses.
The TDS of 50 ppm was obtained from my local water authority. pH value was directly measured by myself. After my posting I did a lot more research and reading on the relationship between pH, KH, GH and PCO2 and also noticed the discrepencies between the TDS value as it related to pH reading. Learning quickly to obtain data first hand. I will run my own values and post the results.

[Eddie]

No worries Peter, even without a TDS meter, just knowing the kH and gH can help alot. If your kH is very low, you can have dramatic changes in your PH, depending on what elements are acting on it. A good or decent kH reading would be around 4 dKH.

Eddie

[waj8]

The TDS reading could be in grains per gram. In that case, everything would make sense.

[kaceyo]

Where I live the tap water has a TDS of 44ppm, Kh is less than 1 and pH is 7.8 to 8.0.
The city adds something, don't remember what precisly, to raise the pH because the combination of very soft water and low pH is hard on the metal pipes, they corrode quickly, and raising the pH slows it down.

[PAR23]

Thank you all for your input. Once I receive my test kits, I will post all the parameters of my water. Sorry for being analytical here but what if the fish tank's pH is 7 just prior to WC matching the tap water's pH while the aged water has a pH of 8, would you still use the aged water for WC? Thanks in advance.

[waj8]

There would be no legitimate reason for your tank pH to be 7 if your aged water was pH 8. Your tank water would also be aged water anyway. That is unless you had a planted tank and were injecting CO2.

[Eddie]

There would be no legitimate reason for your tank pH to be 7 if your aged water was pH 8. Your tank water would also be aged water anyway. That is unless you had a planted tank and were injecting CO2.


That would depend on the water's KH. If its low, the PH could slip down as nitrification lowers KH.