What drives pH high?

[Mordred]

I've had my tank setup for about 5 weeks now, and the pH seems to be steady at around 8 or just below (hard to tell from the test kit).

The tank is reasonably planted, has 6 lemon tetras, 6 cardinal tetras and 2 dwarf gouramis in it. Total volume 200L (approx 50US G).

I have added a laterite substrate to the gravel for the plants, and I added a carbon dioxide generator a couple of weeks ago.

There is a lot of bogwood in the tank, which I soaked for a week before adding it.

The fish seem very happy and healthy at the moment, and there is very little ammonia, 0 nitrite, and very little nitrate.

Wondered what would be keeping the pH so alkaline?

Should I be worried by the pH, and how should I go about gently lowering it? (guess I should aim for 7?).

I would like to add some ottocinclus and corys but have heard that both are very pH sensitive so would like to be certain that the tank is ok before i add them.

[Hans]

check the carbonate hardness of your water, consider mixing distilled with tap to find a happy medium.

[TKOS]

I would stick with a stable easy to maintane pH , rather than a specific pH.

Is this well water or city water?

If you add new fish just make sure to acclimate them very slowly. Take some of the water out of the bag they are in and replace it with a cup of water from the main tank. Do this over the course of up to 2 hours and they shouldn't have any problems with the new pH.

Fresh clean, stable water is the most important thing.

[Mordred]

Town water -

according to the water company website the total carbonate is: 263 mg/l (ppm), which they class as hard.

Thanks for the comments about adding the new fish TKOS - I have been very careful with the ones I've added so far, but considering that I had seen specific warnings about the ottos and the corys I was worried about them.

The tetras and gouramis seem happy.

[Lazersniper]

I have similar issues with high ph and hard water. My ph usually reads at 8-8.4 ish. My friend decided to surprise me with a cory about two weeks ago. I've not had the time to do proper research about this fish but it seems to be doing fine.

I have another fish, according to plenty of websites its very sensitive to water parameters. The ph of this fish is suppose to be about 7.4. It seems to be doing just fine as well. I've only had him for about a 5 days tho as the first one I had did die. However there is a big difference between the first and this one. This one actually hunts for food, and swims around the tank. The first just sat in a corner till it croaked after three days of purchase.

I've not had them for long obviously but so far they seem active and show no signs of stress.

[Mordred]

Great, thanks for those comments Lazer - thats reassuring.

Hope the new addition survives well.