high PH!

[sarahw20000]

I bought a testing kit last night and tested everything. The thing is the water that i fill the tank up with from the tap is PH 7.0 but the water in the tank is 8.4! This seems really high and is definitly too high for the tetra's which apparently like around 6.8. Am i doing something wrong for there to be such a dramatic difference between the tap water and the tank water? The Ammonia and Nitrites are at 0 and the Nitrates are at about 7ppm (the colour was between the 5 and 10 level) and the tanks been running for 3 1/2 months.
Am i panicking for no reason or have i got a problem?

 

[Bloo]

Well you're sitting with a very similar problem to me here in London - where the PH is very high. So is my GH & KH, which makes it more difficult to bring down.
You should check your KH as well - as this will influence how easy or difficult it is to bring your PH down. I My tanks are also about 8.2 / 8.4 and have brought it down by using bogwood - though this is a very gradual process and can take several months. The other way is by introducing CO2, Which I did in my one tank – and within a matter of days it came right down to 7.4

You could also try adding some peat to the filter.

One thing I would not do, is use chemicals to bring the PH down. Once you start doing that it’s very hard to keep constant and regulated.

Is you PH a constant 8.4 ? or is that what it comes out of the tap as ? You migh find that it drops slightly to 8.2 when in the tank anyway.

Edit: Here is a very good article on PH, GH & KH - hope that helps.

 

[sarahw20000]

No thats what i meant, it comes out of the tap at PH 7 which would be ideal, what i was asking was what am i doing to make it go up to 8.4 when it's in the tank?

 

[Bloo]

AH sorry I misunderstood
What substrate do you use ? Did you buy it from a fish store ? Do you have any decorations that was not bought in a fish store ? Do you use filter media specifically for that filter or are you adding anything ?

 

[a.d.wood]

Hi there,

Chances are you have something in the tank that is buffering the pH up from the original 7 to the levels you are finding now.

Common culprits are the gravel and any rocks you have added to the tank. If they contain/are limestone or similar carbonate based material then this is why you're pH is up over 8.

A quick test for your gravel, take some out of the tank and put it in a glass. Add some descaler or vinegar (even better is hydrochloric acid), if you see bubbles rising from the gravel then this is the culprit.

As per bloozoo2's request though, please check the kh and gh (hardness) of the water, the more information the better.

Just another thought, take a sample of your tap water and leave it to sit for 24 hours, then test the pH (just rules out another avenue of enquiry).

Andrew

 

[sarahw20000]

The only thing i've got which isn't specifically meant for an aquarium is a big chunk of slate which i got given with a different tank, could that be the culprit? If i took it out and that was the reason would be PH drop dramatically and stress the fish?

 

[Bloo]

You sould certainly take it out - and yes, that could be the culprit. The PH wont drop instantly, but with water changes it will. That's gradual enough to monitor what happens.

 

[The-Wolf]

Slate in itself is inert; however it can have bands of other minerals/metals contained in it.
IMHO a stable pH is by far better than a continually flutuating one.
Most fish will easily adapt to the higher pH but there as some that just won't, it all depends on what you have/want to keep.

 

[sarahw20000]

Yeah i did actually notice it's got some stuff in it that looks like fools gold but i assumed as it'd been in a tank before it must be safe, that'll be coming out when i get home then!

I havn't got testing kits for kh or gh but i know we have especially hard water in my area because we have a water softener for the bathrooms (not where i get my tank water from) and we have to buy special teabags!

I will do that test for the gravel but that was proper (if cheap) aquarium gravel

 

[a.d.wood]

Hi there,

pH of 7 from your tap and very hard water doesn't sound right. I would expect your tap water to have a higher pH if the water is very hard.

Aquarium gravel can still contain limestone, I'm interested to see what you find.

Andrew