Temper the effects of Large PWC on pH

[pairustwo]

I need to do a large PWC (added new flourite and made a mess and now one fish has a popeye).

My concern is that my tap has a pH of 7.2 and my tank has a pH of 6.4.
I don't get why it falls so low when it sits in my tank for a while but it does.
I don't have peat moss or anything like that in the filter or the substrate.

Anyway it seems that if I do like a 50% PWC I will be dramatically altering the pH of the tank.

Anyway around this?

pairustwo

 

[tkos]

Perhaps a series of smaller changes. Or else can you add some polywool to your filter to increase the mechanical filtration? If you do a series fo smaller changes, get the pH close, then larger changes will be easy.

As for the drop. Have you tried measuring your tap water left in a shallow bowl on the counter for 24 hours.

 

[squawkbert]

The buffering capacity in the tank should far exceed that of your tapwater. This means that a 50% PWC shouldn't alter your pH by more than a 10th or two. If you're worried about it, mix 1/4cup of tapwater (treated w/ prime or whatever you use) & 1/4 cup tank water - combine, mix, compare pH to that of straight tank water. If they're within 0.3 or 0.4 units, I wouldn't worru about it at all. If they're a full unit apart, either do more PWCs of a lower % or just add your replacement water slowly.

 

[pairustwo]

I think I need to buff up the buffering capacity of my tank.

I'm always concerned that the pH is becoming to acidic. 6.4 seems to be on the edge of what is healthy. I wish I could figure out what is draging it down.

thanks for the advice
pairustwo

 

[Argblarg]

You need to measure your tap water after letting it sit for at least a day to get an accurate reading. There could be some driftwood or rocks in your aquarium that are modifying your pH. I would not worry about 6.4 as fish can survive well lower than that.