[Samper]

Ocean Light 250w HQI - Aqua Medic AB
with the 20k bulb and ballast included.

The ballast is magnetic but for now it'll do.

I also got a free surge protector and digital thermometer and extra bulb. Should be here in 4 days so I'll need to figure out how to acclimate the corals to this light. Recommendations are needed.

[Poseidon]

Start HIGH and work your way down... When I went from PC's to MH, I started my bulbs 14" off the water, thru GLass tops... Did that for a couple days, then removed the tops. Left it like that a few more days, then moved the lights down an inch or so every couple days till I got to my current 7" off the water...

[Samper]

I should list my corals and where they are located in case any of you think I should do some rearranging.

Top right of the tank about 1/4 from the top is my maze brain.
To the left of the brain about 5 inches is my anemone.
Below the brain about 1/4 of the way up is my Sinularia and Candy.
Near the bottom below the candy is my Xenia.

To the left of the anemone same height but about 5 inches away are my star polyps and orange zoos.
About 4 inches left of those is my digitata.
Below all that about 1/4 of the way up are my purple ricordia.

On the left side about 1/4 of the way up are my yellow polyps.

Will I need to move any of these? The anemone will move it its own if needed but the rest may need some different placement.

Also do you guys think my inhabitants will appreciate this light?

[Samper]

here are some pics. I'm having trouble switching out between my coralife fixture and the halide due to the size of my tank. I have to manually remove the actinics and 10k fixture while the halide warms up. I've started the light 30" above the surface and ran it for ten minutes yesterday I'm gonna work my way up to a full photoperiod and then slowly start lowering it. LMK how you guys would work out this lighting issue if it were you.


I messed up my wall pretty good as you can see but I can fix it easily. Am also thinking of putting a clip on fan blowing on the surface of the water as well as some sort of curtain system around the light. It's almost too bright to be in the room with it and after only ten minutes of it being on I can tell I'll have heat issues with this tank.

[Poseidon]

The fixture you had before was PC right? I don't think you have to start SO HIGH up. I also think you will need more then 10 minutes exposure at a time to actually get the corals to start acclimating. How about 20" up and run it for 2-3 hours? Then add 20-30 minutes every couple days. If you see a reaction you can always cut back, just don't put the bulb 10" above the water and let in run for 10 hours... I know you know better then that. I think your approach is VERY safe, maybe a little to conservative though.

[Samper]

I just try to do it right, thanks for the tip I'll lower it a little and and increase photoperiod tomorrow.

oh yeah
my old lights were the 260w pc coralife but only half of it was over the tank. Is it necessary to still use my actinics in the morning and evening? If not I'll just put that fixture up for a while.

[Poseidon]

Personally I feel actinics are mostly just for the Viewers benefit. There are lots of very successful tanks that don't use anything other then Halides. For about 6 months or so I was one of them... I just had 2 10K halides. NOw I have a single VHO actinic just to make the color more pleasing to my eye...

PS I just changed the color balance a little bit, is this closer to what you see with your eye?

[Samper]

Yeah that's a lot closer. The camera was junk and that pic was the best I could do.

I really like the way the 20k looks so far but it seems to drown out some colors on my LR. The pc 10k seemed to show more color.

I'm hoping my anemone appreciates the light cause it's the only reason I invested in one this soon.

[Samper]

Would it be ok to just remove the pc fixture, put the halide on a timer starting tomorrow and set the timer to increase the time by 5 minutes every day?

Would everything get enough light for the first few weeks?

[Poseidon]

Sounds like a plan. I would start at 2-3 hours tops then add 10 minutes each day... BUT only change the ON time OR the HEIGHT NOT BOTH!!! If you decrease the distance between the bulb and the tank by 1/2 it QUADRUPLES the intensity of the light in the tank... SO be careful with that!

[Samper]

I moved the to 20". If this were you how would you go about it?

[Poseidon]

I would leave it at 20" and start with a cycle of 2 hours on 1 hour off 2 hours on 1 hour off 2 hours on, then off for the night. DO this for a few days then start decreasing the OFF time, by 10 minutes every couple days. Until you get to a straight 6 on then start adding to the overall period by 15 min each day till you get to your desired photoperiod. This is pretty safe, especially coming from PC's... IF you see any adverse reaction though you can always cut back the time, or increse the OFF periods!

Then you can gradually reduce the height from your current 20" to about 10". I have mine at 7" and have no problems with heat... Do this slowly as well, say 2-3" a week.

[Samper]

I'll do it. Thanks

[Poseidon]

No problem... let me know if you run into any trouble!

[Samper]

The only problem I ran into so far is that my timer only has 7 settings. Each has an on off and I didn't have enough left to run from 6 30 to 8 pm. I'll compensate as the photoperiod increases over the next few weeks.

Once I'm up to a full period I should only run these 6-8 hours max right?

[Poseidon]

Nah... I run mine almost 12. That may be too LONG but it is for MY benefit, I don't get home from work till 10.40PM and I want to watch the tank to calm down... I would think 8-10 hours would be ideal.

[Samper]

Alrighty then

[Samper]

Well...........temperature swings are my next problem. Lately I've been able to maintain between 77-80 degrees. With the halide 5 minutes of it being on the temp starts rising. It quickly got to 86 within 20 minutes. I setup a small fan on my entertainment center and have it blowing across the surface. It took the temp back down to 79 but it's still trying to go up. My digital thermometer keeps jumping from 81 back down to 79, then back to 81. The fan is obviously helping but I don't know how good this is for my inhabitants.

[Poseidon]

THis is on your 20 gallon right? OUCH I didn't even think of it being such a small water volume. Yes you will have heat issues to contend with. The fan is not only going to help keep the tank cool, it is also going to INCREASE your evaporation rate substantially. Can you raise the fan to a point where it blows on the light fixture only? That may help with the evap.

I'll think on this one tonight and see if I can come up with something to help out...

[Samper]

Yes I can angle the fan to blow on the light only.


I have my timer set to turn the fan on only when the lights are on.