High Ph In One Tank

[blinky000]

I have 5 tanks in total and all of them have a pH of 7.6. However, I just tested the water on my downstairs betta tank to make sure it was fully cycled and noticed that the pH seems to be off the scale. It only goes as far as 8.4. At least I should be grateful that the cycle is complete! I've never really had any issues with pH before. What should I do now? The betta seems fine in himself. Would a 50% water change be ok or would the sudden drop in pH do more harm than good?

Here were the rest of the readings:

NO3 - 15
NO2 - 0
GH - 16
KH - 15
CL2 - 0

 

[gatorsean]

if you were using ammonia to cycle the aquarium that raises the pH because it is a weak base.

 

[the_lock_man]

if you were using ammonia to cycle the aquarium that raises the pH because it is a weak base.

Eh? Ammonia in a fishless cycle tends to lower pH, as the nitrogen forms nitric acid.

To the OP, what are you using as a substrate? Do I infer correctly that you cycled the tank with the fish in? Do I also infer correctly that you are using test strips, rather than a liquid kit?

If that last is correct, I would suggest getting a liquid test master kit so that you can verify the test, as the paper strips are notoriously inaccurate. This would also allow you to test for ammonia, which is one of the most vital tests in freshwater fishkeeping.

 

[blinky000]

The tank itself is bare bottom but it does have a glass filled with gravel and a plant. I cycled the tank ( and others) using bacteria from another filter and thus far, it had been brilliant.
They are indeed test strips. They were all I could afford at the time but when I get paid next week, I'll get the liquid tests again.

 

[ZoddyZod]

where did you source that gravel? Do you have the same gravel in the other tanks?

 

[the_lock_man]

Do you have the same gravel in the other tanks?

That was going to be my next question!

 

[blinky000]

Same gravel is in the other tanks too. No problems there. I've had it for years.

 

[the_lock_man]

Same gravel is in the other tanks too. No problems there. I've had it for years.

In that case, my suspicion is an iffy test.

 

[Prime Ordeal]

if you were using ammonia to cycle the aquarium that raises the pH because it is a weak base.

Eh? Ammonia in a fishless cycle tends to lower pH

Only once the AOB have started to do their thing. Ammonia (ammonium hydroxide) is a weak base and will raise the pH slightly to start with.

 

[blinky000]

I think you may be right. I tested again and, though it does look a little higher than it should be, it isn't florescent like the last one. And frankly, I don't trust the readings I've been given anyway. I think I'm going to invest in some proper test kits. I don't like these ones...

Thank you for your detective work everyone