The benefits to having coral or crushed coral in a freshwater sump..if any

[Venom Stinger]

i just bought a 125g saltwater set up -minus the protein skimmer- off craigslist for $150.00
one hell of a deal.
the sump had crushed coral and big coral in it.
i have heard that there is some benefit to having it the a freshwater set up but i cant remember.
if someone could help or send me to a thread that discusses this that would be great.
thanks a lot,
V

 

[KLee79]

Dont know any links, but having crushed coral in a freshwater tank would only affect the ph. For people who want a higher ph crushed coral acts as a natural buffer, so that no additives are needed. Or if your city water is very acidic, it would be a plus to add crushed coral to raise the ph..

 

[anarekist]

water ph can change with the amount of fish waste thats in the water, this can cause a ph swing (where the ph of the water rapidly changes) a ph swing can kill your fish.

with crushed coral in your water, it will release calcium ions into your water raising your ph to around 7-7.6. also your KH / GH also goes up because the dissolved mineral content of your water goes up. This helps to buffer the ph of the water, it will be harder for fish waste to change your ph making your ph more stable thus preventing ph swings that might harm your fish.

i have about 40lbs of crushed coral in media bags just sitting in my sump and i never have to worry a out ph, it's always around 7-7.2 and the ph out of my tap is 6.

 

[carsona246]

jesus 40lbs in one tank, how big is your tank? I use a tiny media bag filled halfway for my 40 and it gets the job done

 

[Venom Stinger]

thanks for all the help guys.
so my last question is....can good bacteria grow on CC?

again..thank you everyone for the help.