sand or crushed coral/rubble

I might be buying a tank that is up and running....For the substrate there is the big rubble/crushed coral.Would it be better to change out the original substrate for sand ??? Or just leave it the way it is. The tank has been running for 3 + years with no problem....

Also  what is the best way to move sand from one existing tank to a new one ?? Do I need to do anything to the sand before I transfer it over (like stirring it up to release gasses and then letting everything settle)

Thanks

Scott

Edited by Schondar

What sizes are the sand particles and rubble and how much depth of each. Total depth?

^^^^^^^

 

thats a bump   lol   up up up

 

What do you want to keep in it?
Some things like big rubble and some like fine sand to roll around in.
Other than that, I think IMHO that it is more of a personal decision.

I like fine sand and so do some of my fish.
But I have seen tanks with rubble that look pretty good also.

It all comes down to what do you want?

If you don't like the rubble, move it to the sump (slowly) and replace it with smaller grain sand in stages.

For many years, as I was trying to help people see that Utah Oolitic was a great sand for marine tanks, I would often point to the fact that less oolitic sand is needed to do the same job as courser sand. Then one day I was reading the print on a bag of CaribSea Oolitic sand. CaribSea's owner Rick Greenfield, a Ph.D geologist and pretty smart guy about substrate, evidently agrees with me.

My experience is that a 3" sand bed of Oolitic will do the same job as 6" of the typical reef sand. Crushed coral would have to be even deeper. I typically use a thin layer of larger particle sand on top of Oolitic. The larger sand is usually CaribSea Special Grade Reef Sand and I include some crushed coral in one area of the tank for a natural effect.

When Rick was here as a guest speaker around 1996 or 1997, we took him out to the Great Salt Lake to check out the sand and get his opinion of whether it would be good for our aquariums. Unfortunately we didn't know about pure Oolitic at that time. I would not be surprised to know that he did. Now he is making money on it!