Changing from a decorated rock and fish only tank to live rock and fish tank

[etcruzan]

I currently have a 55g tank which is setup with 2 powerheads pumps, hang on filter, a skimmer, heater, undergravelbed filter,
decorative rocks/shells,crushed coral and some fish (yellow tang,damsel,green chromis, clown)

I would like to add live rocks to my tank and maybe take out some of the decorative rocks (which by the way most of the rocks and shell in the tank came from the US Virgin Islands Carribean Ocean my hometown, but they are dead not live).

I would like to know if I would need to replace the light if I just want fish and live rocks, and if so what lights would I need? The lights I have right now is the regular lights that came with the tank. Can I just replace the light bulb or do I have to change the whole light fixture?

I have been reading "Natural Reef Aquariums" and your forum and I find that mostly everyone is using sand. I know to use sand I will have to get rid of the undergravel setup which I am not against however, I don't think it is safe for my established tank. I would probably have to redo the whole tank. Do I need the sand or can I just keep the crushed coral?

Thank You for the help.
ETCRUZAN

[griss]

ETCRUZAN,

If you want to replace the crushed coral with sand, click on the search forums button on top of RC. Then type "replacing crushed coral" in the search feature. This will provide you with a wealth of information on how to do so with minimal impact on your existing tank.

If you are going to keep fish only with live rock (FOWLR) you do not need to change you light fixture, but a good 50/50 or 10K bulb would help the live rock.

However, if you want to keep corals in the future, you will need to increase your lighting.

Griss

[slimytadpole]

I'd suggest removal of the undergravel filter. And if you're going to do that, there's really little reason not to switch to sand since you're going to be stirring up everything, anyway. At the very least, you should cap-off the undergravel filter, and stop using it.

[Rock Anemone]

Best deal would be capping the under gravel filter like slimytadpole said and take a little of the crysh coral and top it off with sand, however, under the U/G filter there is probably a lot of mess and if you take it up tocix water can contaminate the tank.... In my opinion i would take the wate rout of the tank keep it in buckets then take the u/g out and crushed coral if you want and replace it with sand then i would slowly put the water back, careful not to disturb the sand. Then put some live rock in and other stuff, use the decortive rock for the back of the tank and disguise it with live rock... there are some types of mushrooms you can keep under your lighting and "sun coral" not sure of the name. lol.

Good Luck!
Rock Anemone

[DgenR8]

I like the idea of removing the UG filter, it's a bomb waiting to go off in your tank. Don't take it out with animals in the tank.
You mention a hang on filter, what kind and what size? The reason I ask is that you have a large colony of bacteria in that UGF and removing it will leave the hang on to handle your entire Bio load.
What I'm thinking is that this will take some time.
First, you need some live rock, cure it externally to protect your fish. Once cured, you can remove most of the water from your tank along with your animals, pull the UG, clean the tank really well. set up a sand bed, add water and live rock, add your fish.
That's what I think.....

[jscott]

et, during the course of conducting graduate research I converted two, 29G plenum style tanks to 4", dsb tanks. The sand was similar in grain size to special grade reef sand. It was collected live, from a reef area. I was hoping to achieve denitrification through use of the plenum system. This did not occur until after several months of trials of the plenum tanks, when I converted the plenum tanks to dsb tanks. Nitrates dropped to undetectable levels within 3-4 days. I went on to establish 6 more dsb tanks, adding fairly equal portions of now cultured live sand, with store bought special grade reef sand. In each instance, nitrates dropped to undetectable levels within 6 days.

I'd definitely lose the ugf. Make some new s/w with RO/DI water, get a cheap Rubbermaid tub, add 50/50 new and old water to the tub, place your decorations and fish in there, and aerate it. The fish should be OK for a while, while you work on your tank. A partial w/c may be needed, monitor water chem. Remove your ugf plate, add some special grade reef sand and gently mix the two, let the muck settle out and carefully siphon it off the surface of the sandbed. Only shut down the hang-on filter long enough for the muck to settle, then fire it and the powerheads back up after you've topped-off the tank with new s/w. I'd be willing to bet water chem will stabilize in a very few days, enough so that you can add your new rock. Make sure it cycles properly before adding your fish. Monitor water chem, this is the step you do not want to rush. As said in an earlier post, if you keep only fish your existing light should do. I'd bet you'll want a better light, the rock would do better with it.

hth...and I hope I didn't miss any major steps...it's getting late!