Rising PH

[static]

Hi all just a question about my PH.

I have a newly set up aquarium that has cycled (no fish).
The water parameters are as follows -

Ph 8
Ammonia 0.0
Nitrites 0.0
Nitrates 5
Kh 1 degree on german scale.

The thing is I have water that has a ph of 6.8 out of the tap.
The aquarium is bare bottom with a sump filter with foam bio balls and ceramic noodles. It also has a couple of pieces of drift wood which should lower the ph as well.

Why would the ph rise to 8 when I have nothing in the tanks to lift it?
If I leave the tap water in a bucket for 24 hours no ph change so I am confused as to what is causing the rise.

[DJW]

You have nice tap water. When you tested aged water in the bucket I assume that you were aerating it? The only suggestion I have is that if you measured the pH right after dosing the tank with ammonia the pH would be high. When I add just 1 ppm of ammonia the pH will rise immediately and then fall as the ammonia is consumed. Some fishless cycling instructions have people putting up to 4 ppm of ammonia, which IME is way too much and could push the pH over 8.0

[Cosmo]

If your tap water contains high levels of C02 it will test lower out of the tap than it will after being aged and aerated. My tap water is about 7.35 out of the tap and almost 8 after aerating for 12 to 24 hours. I use food grade phophoric acid - .85% to lower the ph back down to around 7.2. You won't have a problem with ph8 water unless you're looking to breed so long as you age the water overnight first (plenty of aeration) If you add it to the tank straight from the tap your fish could become stressed by the changing ph - if you can't age change less than 50% (or even 40%) of the water at one time so the water in the tank can buffer the new water and lessen (or elimenate) the ph shock.

[DJW]

The OP has tested his water for pH swing and doesn't have any. He is wondering why the pH is going up in the tank from 6.8 to 8. This is a bare bottom tank so no gravel.

Cheap carbon can do this, or the ammonia that is being added to keep the fishless cycle going. I can't think of any other cause. There are some ceramic bio media that will cause a temporary rise in pH, but not this much.

[Cosmo]

Is it being aerated in the bucket or just left in the bucket - original statement on clear on that

[LizStreithorst]

The only thing that I can figure is that he didn't aerate the bucket. That is a huge swing. The OP will have to age his water, for sure.

[static]

Thank you for the info and replies.
I have put peat moss and the tanks seems to be stable at 6.8.

With the research i have done because my water has a kh of 0 shouldn't that mean that there is nothing to buffer the water to a higher ph?

[DJW]

The first thing you need to do is find out if you have a big pH swing. The pH doesn't matter unless you are breeding, but the pH swing does matter if it moves more than 0.3 or 0.4 during ageing.

In an earlier thread you said the pH straight out of the tap was 8. In this thread you said the tap is 6.8 and going up to 8 in the tank. A KH of 0 to 1 and a pH of 8 doesn't really add up. You need to systematically measure the pH swing in a bucket after 24 hours with aeration (no peat) and compare the resulting pH with the pH from the tap.

[static]

Yes you are correct the ph was 8 out of the tap through a carbon filter but I have put a line from before the filter and am getting consistent 6.8. Ageing outside of the tank doesn't seem to change anything it only changes once the water is in the tank.
From what I have read no kh 0-1 and ph of 8 doesn't make sense to me but you are the only person to confirm this so far.

[DOJOLOACH23]

If doing 50-75% Water changes, what is an acceptable PH range between the tank water and aged/new water? So that it doesn't stress the fish?

[Phillydubs]

As close as possible without using additives is my best bet. consistency is key, the fish will adjust just keep it consistent