Difference in quality of live rock

What is quality live rock. Most will say that quality live rock should be light and porus and riddled with small pore like holes. Fiji rock been the most common type to fall into that category. Most Fiji live rock comes in as grade A rock due to it been larger and more porous than rock collected from other places such as Tonga and the Caribbean were the rock tends to be more dense. Other cheaper rock and coral rubble (Which most live rock is) collected from the shoreline is of lesser quality as it can harbour parasites and viruses due to been out of the water and in sunlight for numerous hours a day. Another form of rock is made up of lava and also calcium carbonate skeletons of dead corals which fuse together over a long period.
Porous rock allows for for amounts of denitrifying bacteria to grow within the pores, turning the rock into biological filteration.
Cured and uncured live rock.
The majority of rock sold here is not fully cured though sellers claim it is. Alot of people setting up a first marine tank aint aware of this and wonder why they have problems after adding this rock to their systems. The things to look out for are
1. Does the rock smell/stink
2. Still dead matter and organisms on the rock such as sponge etc
Rock like this that contains die off will pollute your system in the form of ammonia and nitrites.Which in turn will prolong the cycle of a new system.
IMO anyone adding such rock to a new system should leave the rock out of water and clean off as much dead matter as possible and also most unwanted hitch hikers will surface during this period and can be disposed of as required.
Fully cured rock which some shops claim to sell, should have been cycled until the rock is free of all die off and bacteria has started to grow in the pores. This i have rarely come across.Most shops have a vat full of stinking rock thats been heavly skimmed and still uncured.

On saying all of the above i personally question if porus live rock is as good as its made out to be. Ok its acts as a biological filteration when first introduced into a system but over time corraline algae forms on the rock blocking those pores and also sticking a coral to rock with milliput or glue will also block pores making the rock no longer been able to house denitrifying bacteria. What now is the difference between what was once expensive porous rock and dense rock that can be purchased alot cheaper?????????????????

Interesting read and honest opinion about the live rock for sale as you have seen it in our LFS. So what rock do you have in yer tanks Gerr and what rock do you reckon is the best to source for a marine setup?

mickdeja wrote:Interesting read and honest opinion about the live rock for sale as you have seen it in our LFS. So what rock do you have in yer tanks Gerr and what rock do you reckon is the best to source for a marine setup?

Hi Mick. The best rock to use when setting up a marine tank is second hand rock from an established tank. Two advantages of doing this is that rock will be full of life and will host copepods and amphipods etc and also it will cost a fraction of the price of what the shops are charging. There is plenty of second hand live rock for sale on nearly all forums so sourcing it would not be a problem.
Some will disagree that second hand is better simply because if the seller has high levels of phosphates etc in their tank that they will leach from the rock into your system. The amount of phosphate absorbed in the rock will be alot less than that in a piece of uncured rock. Plus the cycle process will filter out all the bad elements.

When i first set up my system i used a mixture of second hand live rock and also dead live rock. You cannot tell the difference now to which was the dead live rock as it all is now full of growth and life.
Live rock itself is not alive its what has grown on it that makes it alive.