Does coral increase or decrease pH in a freshwater aquarium?

Answer 1

Well it doesn't actively effect the pH of the tank at all. But crushed coral, and to some extent larger coral will increase the hardness of the water. This has the effect of buffering the water and results in a higher pH.

Answer 2

It will increase the pH, but not as high as others here have mentioned. I keep three saltwater tanks and have a crushed coral or aragonite substrate in all of them. When I moved to an area with a different water source (my previous tapwater had been 8.3, the new 7.0), it would only raise it to 7.8.

To raise the pH, it slowly dissolves, releasing carbonate into the water, which is what raises the pH, but at the same time it releases calcium and magnesium, so it raises the hardness as well. If you have fish that prefer hard, alkaline water (some cichlids, livebearers), a small mesh bag of crushed coral in your filter (small change needed), or as a substrate (larger change needed) will do this for you.

If you're planning to use a piece of natural coral in a freshwater tank, consider that it will not only raise the pH and hardness, but will dissolve over time. If you want coral for a decorative purpose, it would be better to use a replica - it will look better and hold up much better in the long run.

Answer 3

If you are talking about dried or dead coral, it increases the PH in fresh water. Depending on how much you have in the tank, it can raise the ph to around 8.2.

Although most fish are fine in a wide variety of PH, If you just like the look of corals in tanks, Pet stores now sell a wide variety of Resin corals. Made with poly resin they look like real coral and will not raise or change your PH.

Answer 4

They definately increase the ph of your water


EB

Answer 5

I'm not sure, but I'd assume that it would increase it because it has to buffer the seawater to 8.2.

~ZTM

Answer 6

Increase

MM

Answer 7

second mubuna