Does Crushed Coral Increase pH?

[Buzz1329]

I know this is off topic, but would running a canister filled with crushed coral increase the pH of a freshwater tank?

Mike

[bertoni]

A bit of the crushed coral might dissolve if the pH got low enough and the water doesn't have anything in the way of alkalinity. That might raise the pH a bit. I am not all that proficient with freshwater aquarium chemistry, so I don't know the details.

[Dan_P]

I know this is off topic, but would running a canister filled with crushed coral increase the pH of a freshwater tank?

Mike

I can't answer that question directly, but you could run a small scale experiment to answer your question.

On a separate note, I ground up aragonite sand and mixed it with distilled water. I measured the pH to be 9. The experiment I was trying to perform did not pan out so I did not bother to repeat this pH measurement. Even though the pH meter was calibrated, this high pH result does not make sense to me.

[Buzz1329]

A bit of the crushed coral might dissolve if the pH got low enough and the water doesn't have anything in the way of alkalinity. That might raise the pH a bit. I am not all that proficient with freshwater aquarium chemistry, so I don't know the details.

Thanks!

[Buzz1329]

I can't answer that question directly, but you could run a small scale experiment to answer your question.

On a separate note, I ground up aragonite sand and mixed it with distilled water. I measured the pH to be 9. The experiment I was trying to perform did not pan out so I did not bother to repeat this pH measurement. Even though the pH meter was calibrated, this high pH result does not make sense to me.

You're right. 10 gallon aquarium with crushed coral in power filter is in order.

Thanks!

Mikw

[Arthur1]

yes

[disc1]

I don't know that it would necessarily raise the pH, but it would sort of put a floor on it. Below a certain pH (7.6 or so) the crushed coral would start to dissolve and that would stop the pH going any lower. But it also raises the hardness and calcium levels in the process, so it depends what type of fish you're keeping whether or not that is a good thing. For example, African cichlid keepers often use crushed coral for a substrate or under their substrate as a way to keep the hardness up and the pH from falling.

[tmz]

Many years ago when I kept freshwater aquriums. I put a sea shell in the tank for decoration. Couldn't figure why the water was milky until I removed it.

[Buzz1329]

I don't know that it would necessarily raise the pH, but it would sort of put a floor on it. Below a certain pH (7.6 or so) the crushed coral would start to dissolve and that would stop the pH going any lower. But it also raises the hardness and calcium levels in the process, so it depends what type of fish you're keeping whether or not that is a good thing. For example, African cichlid keepers often use crushed coral for a substrate or under their substrate as a way to keep the hardness up and the pH from falling.

Thanks for the response and especially for walking me through your reasoning.

Mike

[Arthur1]

Sorry Buzz about being so vague. In the freshwater world, crushed coral has been used for many years in African cichlid tanks, not West African cichlids but cichlids from Lake Malawi, Lake Victoria and Lank Tanganyika and some people used it to a degree for their livebearer aquariums as well, such as with mollies. The reason being, is that it increased the pH and water hardness of the aquarium water.

[Buzz1329]

Sorry Buzz about being so vague. In the freshwater world, crushed coral has been used for many years in African cichlid tanks, not West African cichlids but cichlids from Lake Malawi, Lake Victoria and Lank Tanganyika and some people used it to a degree for their livebearer aquariums as well, such as with mollies. The reason being, is that it increased the pH and water hardness of the aquarium water.

Thanks for clarification. I too once had a rift lake cichlid tank and used crushed coral substrate to keep ph at 7.6 (using 7.0 tap water). But I was recently challenged on this assumption and wanted to do a sanity check.

Mike

[tmz]

Argonite( crushed coral) more specifically the calcium carbonate which is it's major component will begin to dissolve at pH under 7.7 or so contributing carbonate alkalinity and raising the pH . So whether you want to use it or not depends on the ideal alk and pH conditions needed for a particular species of fish.

[Buzz1329]

Argonite( crushed coral) more specifically the calcium carbonate which is it's major component will begin to dissolve at pH under 7.7 or so contributing carbonate alkalinity and raising the pH . So whether you want to use it or not depends on the ideal alk and pH conditions needed for a particular species of fish.

Thanks!

Mike

[Arthur1]

Mike, no problem. I grew up old school in the freshwater world and miss it lol. There are so many cool freshwater fish and most people have no clue bc they're specialty fish, expensive or very rarely exported. Enjoy it!

[tmz]

You re welcome.