What will happen if I redo my tank

[justin100]

If I was to take out over 80% of my water, all my live rock, and redo my crush coral substrate with sand would I have to recycle my tank? Is there any other way to redo my tank? Thanks

[cpreefguy]

Why take 80% of the water out? Are you going to take the crushed coral and put a different sand in?

[justin100]

In order for me to take out all the crush coral I have to take out the 60+ pounds of LR I have. Also I read that if you mix up the stuff in the crush coral it could harm your fish. I think thats what happen to my fish last time I mixed up my crush coral.

[cpreefguy]

I would take out 80% of your water and rock and store it somewhere. Then take out the remaining 20% of water and the crushed coral, put your new sandbed in and then replace the rock and 80% of water and 20% new water. This way you wont be taking out too much. Since you are still using established rock and established water, nothing bad should happen to your tank inhabitants.

[NaCl_H2O]

Anytime you remove & replace LR you will get some die off and system cycling. How much depends on how well you preserve the rock and it's placement. If a rock was in full light with assorted growth, and you turn it upside down, or otherwise shade the growth it will die off to some extent.

Crank up your skimmer and keep your livestock in a holding tank for a week or so if possible. Otherwise run carbon and maybe a nitrate sponge for a few weeks.

You plan to remove the last 20% of water & crushed coral sounds right to me.

[scuba_steveo]

I do not think the amount of water you keep matters so much. This is just like doing a big water change, more is better I would think. Here is what I did when I moved my 37 gallon from Austin to SA and went from crushed coral to arag alive special grade all in one day.
1. Filled an ice chest with tank water and added the fish, inverts, and the rock with corals attached.
2. All other rocks went in another bucket with tank water.
3. Took out the remaining water and the crushed coral out of the tank and trashed it.
4. Moved the tank and ice chest from Austin to SA.
5. Set up the tank, added the new sand, laid a piece of plastic over the new sand, added 100% new salt water slowly on to the plastic careful not to stir up too much sand.
6. Remove the piece of plastic
7. Add the rocks w/o corals on them - this helps clear up the tank
8. Wait till night - until the cloudy went away.
9. Add the items in the ice chest minus the old salt water.

This worked for me w/o any loss. I think it was because I used the arag-alive which is sold wet. If you get dry sand it clouds up so much that it may take days to clear.

What size tank are we talking about here? How many pounds of sand do you need?