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Crushed Coral 1 Pound

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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 53 reviews
Exactly What I Needed

Was exactly what I needed for my cichlid tank. Have always had a great experience with aquarium Co-op. It’s my go to business for any of my aquarium needs!

Magical Crushed Coral

So you are thinking about buying this product since you have herd Cory talk about it, try it out. If you have softer water it will buffer your Alkalinity and allow you to have higher PH, it slightly raised the hardness of my tank but not a ton, My water is in the middle of Well and Soft (city water) I tried it out in a new tank and so far im liking the results. Just wash it first or you will have a white cloud of dust! Thank you for the super fast shipping and service Co-Op Team!


Fulfilled as advertised.

Perfect Size

Perfect size! The team at the Co-Op makes it easy. Rinse it very well and plop it in your tank. Instant buffer. I am using the recommended amount. Fast easy delivery! Cory has an excellent team in place! My go to supplier.

Crushed coral

Got this for my tanks. Had issue with tanking pH level . Only been couple of weeks so will see if it helps. But I am sure it will. Cory and his crew haven’t steered my wrong yet.