Can I Use Aragonite Substrate in a Freshwater Planted Aquarium?

[Abby W]

I was recently given a 20 long with a filter and heater, along with aragonite sand and reef rock, as the previous owner was going to set it up as a reef tank. I'm wanting to set it up as a low tech planted freshwater tank (possibly with CPDs or a betta, no cichlids), and I was wondering if I could still use the aragonite substrate? I'm planning on adding driftwood, so that might lower the pH a bit, but would the aragonite cause too much of a pH spike for plants? I'm not adding CO2 and my tap water runs slightly acidic. I have had success so far with freshwater sand and root tabs in my other heavily planted tanks. I have some pebble substrate I could use as well, but I'm worried that large pebbles won't hold root tabs for stem plants. I want to try to use what I have, but I don't want to try the aragonite unless I know it is safe for my tank.

[Ninjoma]

On 12/15/2022 at 2:27 PM, Abby W said:

I was recently given a 20 long with a filter and heater, along with aragonite sand and reef rock, as the previous owner was going to set it up as a reef tank. I'm wanting to set it up as a low tech planted freshwater tank (possibly with CPDs or a betta, no cichlids), and I was wondering if I could still use the aragonite substrate? I'm planning on adding driftwood, so that might lower the pH a bit, but would the aragonite cause too much of a pH spike for plants? I'm not adding CO2 and my tap water runs slightly acidic. I have had success so far with freshwater sand and root tabs in my other heavily planted tanks. I have some pebble substrate I could use as well, but I'm worried that large pebbles won't hold root tabs for stem plants. I want to try to use what I have, but I don't want to try the aragonite unless I know it is safe for my tank.

At least according to CaribSea, aragonite helps maintain a of 8.2 PH. That would probably be too high for most (maybe all?) freshwater tanks. You could probably mix it with regular gravel or sand, (about 1 pound per 10 gallons) to help mineralize your water and stabilize the PH though.

[Expectorating_Aubergine]

If you're going to have aragonite and reef rocks, then you might as well make it an African cichlid tank. You could also do livebearers, as they like hard water too. Plants don't mind hard water. Especially plants like vallisneria. Many true aquatic plants (most aquarium plants are amphibious) actually get their CO2 from calcium carbonate in the water. 

Edited December 16, 2022 by Expectorating_Aubergine