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Crushed Coral 1 Pound

$ 49.00 until FREE shipping

Crushed coral is a great tool for raising your pH. We personally use it at 1 pound of crushed coral per 10 gallons of water when mixed in with our gravel. Crushed coral dissolves over time continually. The lower your pH is, the faster it dissolves. As the pH rises, it slows down how fast the crushed coral dissolves. We find that Crushed coral may need to be replaced every 1-2 years depending on how low of  a pH the tap water is. 

Crushed coral adds a bit of hardness to the water but not much. It does add a lot of kH which buffers the water from pH changing.


When using it in your filter, crushed coral will dissolve faster. This means you'll usually use smaller amounts but replace it more frequently from to 1-3 months being most common.

Customer Reviews

Based on 62 reviews
Great crushed coral

I have soft water and I needed this to raise the pH and it works great

Great Buffer!

Have one pound bag for each 10 gallons in my 20L and 10, this stuff is great! Just rinse and mix with substrate to buffer your water. Great purchase...

Just the amount I needed

Just wanted I needed to stabilize my ten gallon, good price, fast shipping, great educational info as
usual from Aquarium Coop! Thanks!


I bought a little just to test.. works great, ty!

Seems to be helping

I have a heavily planted tank and I noticed that my plants weren't doing as well as they had been even though I was dosing weekly with easy green and my snails shells looked like they were dissolving. Tested the water and realized that it was too soft. So I ordered a bag of crushed coral to throw in my filter and one of those wonder shells. The combination of the two seems to have solved the problem and everything is doing well again.