Converting from CC to Sand... what the best way?

[MOHFpro90]

Ive recently bought 160lbs of CarribSea Live Sand from my LFS on a great sale (Bogo @ $23, 160 lbs for $100 :D). Ive got about 3" of crushed coral substrate right now, but want to convert to the sand. The owner of the store suggested I get a large clear hose, and literally siphon the crushed coral out. I have a spare tank (50gal) and around 20gal worth of buckets. Basically I was thinking about doing half of the tank at a time. Move all of the live rock down to one end, siphon out the crushed coral, and refill the water supply in the tank with new premixed RO. Then, move all of the LR to the empty end, remove the rest of the CC. In regards to adding the LS, Ive read about using a funnel and tube to literally drop the sand straight onto the bottom, as well as putting the bag on the bottom of the tank and slowly and softly pouring the sand in.

I have a feeling that siphoning the CC out will take most of the waste and unwanted junk with it. Also, not reusing the water Im taking out and replacing it with new RO will help keep the water balance.

The tank is a 125gal tank, 140 lbs of LR, 25 ish gal sump, in sump skimmer and fuge. I have a Sailfin Tang, Coral Beauty, 2 False Perc's, 2 chromis, 5 damsels, bicolor blenny and a spotted hawkfish. 1 condy anemone and 1 skunk cleaner shrimp.

Here are my questions:

1. Obviously this large of a change in the tank is going to throw the water balance off. The tank is going to cycle; how much is my worry. Can someone input something here?

2. Should I keep my powerheads on during the transition? Will this help the water maintain quality? Should I remove my livestock(a serious pita, will take probably 3 hours alone to get the buggers outta there)?

3. Anyone have any ideas or suggestions about better methods to go about this procedure?

[Toddrtrex]

[welcome]

Sorry for the short reply, but I did something very similar 3 years ago, here is a thread about it,

http://www.reefcentral.com/forums/showthread.php?t=1233581

[MOHFpro90]

Todd,

Dang, nice tank! :D The more I think about it, the more I am leaning towards using my 50gal as a quarantine tank for the LR and livestock during the process. Im now thinking I will follow this plan:

First day:
-Fill 50gal with display tank water.
-Fill two rubbermaids with tank water.
-Transfer all LR and livestock to 50gal.
-Remove CC and empty display tank.
-Fill display with sand, rubbermaid water/new water. Turn on powerheads and filter.

Second day:
-Transfer LR to display.
-Transfer livestock.
-Do remaining water change from 50 gal.

Or I can stick with my other idea of doing half of the tank at a time, wait a week or two and finish with the other half to prevent any major spikes.

[rivoth]

I think you'll lower your risk a lot by going with newer option of transfering your stock out. One additional suggestion would be to slow down the move back into the tank by first moving some of your live rock back to the display without livestock. Then wait another day and test your water, partcularly ammonia. If the water looks good then transfer the rest back, if not then wait longer.

[Ethan_W]

i just used a net to take out the crushed coral that was in my tank. although i didnt have any livestock or live bacteria to worry about

[03sonicstang]

Its funny, I was thinking about doing the opposite, Sand to CC :)

Now about 10 weeks into my tank the Bahama sand has seeded and is finally staying somewhat put. But you're using Live Sand so it should not take that long !

[MOHFpro90]

Well Ive decided to go with option number 2, like you suggested rivoth. I will monitor my levels myself, and make sure the water is good to go before transferring everything back over!

Oh, and I have decided that while I have the tank empty for a day or two, I am going to take out an interior wall and put the tank between 3 rooms. :D