Ph Dangerously High?

[tintin]

My tank has been established for a few months now and all appears fine. I have had just one casualty - a male guppy - about 8 weeks ago.

I also have a fixed routine of changing 25% of the water every week as well as vaccuming the gravel and changing the filter media.

The fish all appear fine but this weekend I did my first water test in a while and was worried to get a pH reading of 8.4. All other stats were ok 0 nitrites nil, ammonia nil, and nitrates 40 (its never got below 40 the whole time I've had the tank.)

Give the fish I have (see sig), would they be ok if the pH stays at this level? What symptoms should I look for if this is going to be a problem?

TT.

 

[wetwetwet]

Many of your fish would prefer lower pH...

...but messing with water chemistry can be difficult and a bit hit and miss. What are your dealers water params like? What pH out your tap? Is there something in the tank raiseing the pH?

Many captive breed fish have been 'aclimatised' to conditions other than those they would be in in the wild and are therefor much more adaptable than their wild caught cousins...

hth

 

[The-Wolf]

do you have any kind of rock in the tank? is so what rocks?
this maybe the source of your high pH.

 

[tintin]

I do indeed have a rock! Its coral (I think) that I got from a LFS. Its completely loved by my pyjama catfish. He lives in it 24/7.

I've done a test of the local tapwater and it comes in at 7.4pH. I did the tank this evening and its reading a less-scary 8.2. Again, this seems to point towards the rock (there's no other 'furniture' in the tank other than the live plants.)

So the suggestion is that the fish may have well got used to the higher pH, yes? And if not they would be gettting stressed, diseases, etc?

TT.

 

[The-Wolf]

There you go it's the coral making your pH high, remove it and your problems will go away.
I have a pinned topic on rocks here that may help you.