Need some advice.

[ghofmann]

I just upgraded the lighting on my 20L nano from 110 wats of PCs to an Aqua Medic Oceanlight 150 watt HQI metal halide with an icecap 10k bulb with 110 watts of 03 actinic PCs. This gives me a grand total of 360 watts on the tank. Right now the tank has a 4" DSB and about 15 lbs of live rock. I have an emperor 400 (without the biowheels) to run filter floss and carbon and a Hagan 201 powerhead in the tank for flow and filtration. The tanks only occupants are some astrea snails, blue leg hermits and a cherub angle. The tank has been set up and running since August after I tore it down due to a nasty aptasia outbreak. Water parameters are Calc-410, Alk-9.2 dkh, Ammonia-0, nitrites-0, nitrates-0, Ph-8.2 Temp-79 to 81.

OK now to the point. I was thinking of moving all of the corals from my 55 to the 20 and just leaving the fish, live rock and an anemone (that my maroon clown is quite attatched to) in the 55 until after the first of the year when I set up my new 75. There are not a lot of corals right now in the 55 so I don't think I'll have a problem with overstocking the 20. My main question would be how should I aclimate the corals to the new light or will this not be a problem. The 55 has 260 watts of PC lights on it. Also by adding the corals and the rocks that they are attatched to I will be adding another 15 to 20 lbs of live rock to the 20 to help out with the filtration.

Here's a list of the corals that will be going in to the 20.

Purple Tipped Frogspawn
Torch
Open Brain
Pulsing Xenia
Various Zoos
Green Star Polyps
Frilly mushrooms
Green Striped mushrooms
Encrusting Monti
Small Bubble
Kenya Tree
Colt Coral

Please let me know if you see anything wrong with me doing this.
Thanks

[Reefland]

You will definitely need to acclimate the corals to the new lighting. There are a couple of ways to do this but neither of them is "easy". One way would be to raise the light significantly above the water and slowly lower it over time. Raising it would take away some of the intensity the corals received and it would gradually increase as you lowered it. Anotehr way which is probably easiest is to use some regular screen and put several layers of it over your entire tank and gradually remove a layer until it is all gone.

[ghofmann]

Thanks Scott.

I was thinking about this as an option also.
If I just ran the PCs on the 20, 110 watts with one 10k and 1-03 for the regular photo period the corals are used to and add the MH at an hour or two for a couple of days and slowly increased the time that the MH was on to the normal photo period and then swithch the PCS back to both 03 actinics after a couple of weeks of letting the corals adjust to the MHs.

[Reefland]

That's a possibility as well. I like the first two options as a more effective means of acclimation. It just seems to me that even though the method you suggest is providing a much reduced photo period, for the time the light is on the corals are receiving much more intense lighting then they are used to. Not saying it won't work, just my opinion.

[ghofmann]

Right now I have the MH about 12" from the water and the pcs are at 10". How far from the water should I start with the MH?

[Poseidon]

I would use the shade cloth and leave the bulb where it is. If you raise it to much more I think you will have to much light spill into the room and distract you! ;) Maybe 2 layers to start, leave it for a few days, then 1 layer for a few more days then none. Should be a good place to start anyway.

[ghofmann]

OK I guess the screen probably would be the best idea so I'll give that a try and let you know how it goes. Thanks for the input.

[Reefland]

Never thought about shade cloth. The only reason I mentioned the screen (and shade cloth now) as not being "easy" is because typically you have to go out and buy some, it's not something that is commonly lying around.

[zhenya]

Hi Greg,

I would add another question for you. You listed quite a few corals in your list and this made me wonder as to how all of them will fit into the 20g tank without any issues? I mean some of them are quite serious competitors, Euphyllias and Plerogyra are some of them but some of those mushrooms can be a real PITA as well when it come to war times.
Do you have enough room in there?

[ghofmann]

Hi Greg,

I would add another question for you. You listed quite a few corals in your list and this made me wonder as to how all of them will fit into the 20g tank without any issues? I mean some of them are quite serious competitors, Euphyllias and Plerogyra are some of them but some of those mushrooms can be a real PITA as well when it come to war times.
Do you have enough room in there?

Gene I've decided to leave some of the softies in the 55. The only things that are going into the 20 are the LPS, monti, some zoos and xenias. There should be enough room in the tank for them.

I found some old nylon screen laying around and decided to use that for acclimating. I put three layers under the lights and it seems to have cut most of the MH light down to nothing. Tommorow I'll aclimate the corals to the water and put them in.