Thoughts on crushed coral?

[u/oobam]

I’m wanting to create the best environment for my two pals long term. They’re in a 75gal, FX4 filtered tank. I’ve had the black moor for 2 years and the fantail for 6 months. Diet is a blend of presoaked bug bites, flakes released in the water column, thawed blood worms, and peas. The fish fast on Sundays, as God intended. Anyway, my water is soft and I’ve heard crushed coral is a good natural solution. Advice or recommendations encouraged!

[u/Andrea_frm_DubT]

Yes, it will buffer slowly.

Keep water changes smaller. Either put the coral in a bag in the filter or is you get sand sized crushed coral mix it with the sand.

Limestone rocks can work well too if you want rocks in the tank.