How Do I Keep A Higher Ph?

My tap water’s pH is pretty high, but once it gets in my tank it lowers to about 6.4-6.8. I have two fantail goldfish and I’ve read that they thrive in pH’s of 7.4-7.8. In the past month, I’ve used baking soda to bring up the levels, but as of today, they’re back down to 6.6ish. I need something that will bring up my levels long-term, but will not exceed 7.8. What should I do?

 

Sounds like your KH (carbonate hardness) is low. This is what maintains your pH at a steady level.

I suggest some crushed coral in your filter. This will raise both KH and pH.

Also, test your nitrates. Higher nitrates cause your pH to drop.

 

How much crushed coral do you suggest? I have a 30 gallon tank. My filters are already stuffed so I may have to buy a small 10-gal filter and fill it with the coral. My nitrates are less than 10 ppm

 

How much crushed coral do you suggest? I have a 30 gallon tank. My filters are already stuffed so I may have to buy a small 10-gal filter and fill it with the coral. My nitrates are less than 10 ppm

In a 20 gallon at work I use a golf-ball sized portion in a media bag to maintain a stable pH and KH. Something of similar size or slightly larger should work just fine.

 

I typically advise people that it should be 1 cup to 40 gallons, so 1/2 cup ought to do it. Though you could go less and keep track of it and add as you go as well.

 

Does it ever need to be replaced?

 

Does it ever need to be replaced?

eventually you will have to add more. It raises the gh/kh as it very slowly dissolves. It isn't like carbon that has to be removed and replaced with new because it stops doing its job. The crushed coral will just continue to dissolve and keeps on working until it is all gone. Keep in mind that you can't actually see it dissolving because it happen very very slowly.