[jbrianchamberlin]

Just set up a new 75 gallon tank yesterday. Just have the canister filter running, the heater of course, no fish yet. The temp is where it should be and while the water was very acidic at first, the PH seems to be coming up a bit. The water seems yellow though but I can't tell if ti's just because of the gravel (natural) or the drift wood etc... I don't have any plants in it yet. Will this eventually go away? Never ran a tank this big before.

 

[susankat]

Sounds like the driftwood is releasing tannins into the water. Did you soak or boil your wood before putting it into the tank. If you have a pot big enough you can boil it for a couple of hours and that will help, if not put it into something and pour boiling water on it and let it set for a couple of days changing out the water a couple of times a day.

If you don't want to do that, add carbon to your filter and do large water changes till it clears up, which can take awhile.

 

[Dmaaaaax]

There is nothing wrong with tannins in the water and most South American fish like this which is why you can buy "Black water extract" seperately...which is basically tannins.

However, it does seem weird that if it is tannins that your pH is going up. Usually driftwood drops your pH.

 

[jbrianchamberlin]

Maybe I'm getting the terms mixed up. PH when I first checked was like 6, maybe even lower. Now it's like 6.7.

The driftwood was already treated... I just cleaned it really good.

 

[Saprobic]

Pre-treated driftwood can unfortunatly mean a lot of different things and certainly doesn't mean this isn't the source of your tanins.

There is a very small chance that it is not tanins (entirely) and could be a phytoplankton outbreak. Some acidic water species do use brown photsynthetic molecules instead of chlorophyll. But if this is the case as the organisms settle you will start to see a brown film covering everything.
In either case active carbon in your filter will help. If it is phytoplankton keeping light off the system will help too.

Lots of water changes will be required also to reduce the nutrient levels.
The advice you have already recieved is good and most likely to be accurate, but in the off case they are wrong I hope this will help.

 

[ladyonyx]

It's probably the driftwood releasing tannins, which isn't a problem unless you hate the look of yellow water. Though the phytoplankton outbreak is possible too. Either way, all the advice above covers it.

 

[susankat]

Maybe I'm getting the terms mixed up. PH when I first checked was like 6, maybe even lower. Now it's like 6.7.

The driftwood was already treated... I just cleaned it really good.

Thats because as the water sits it will outgas and the ph will go up some. If it has been in the tank for a few days then there is a possibility that there is something in the tank that is raising it. Such as substrate, rocks and some deco.