MH-From 150w to 250w

[LinkinPark]

Currently, I am using a 150w DE MH which is @ 10inch above water surface. My DIY 250w will be done (by Calcium Reef) soon and I would like to know how to acclimatize my corals to the new fixture.

Pls advise

[Achilles Tang]

Do you have any way to lower the new light fixture incrementally? Say from 15inch to 14 to 13 to 12inch over a period of 1 or 2 weeks?

If you can't you can always shade the new lights with a cloth or something to cut out the UV.

[Morgan]

Hi LP

You can try AT method or you can have shorter photoperiod.

If your current lights are turn on for 8~12 hours a day then with the new 250W you can start with 5hrs and slowly work it up from there. Observe for signs of bleaching especially for acros........pay more attention if yours are DE bulb.

UV radiation is very high and might cause problem.

[LinkinPark]

Thanks, AT & Morgan

After a long period of observations (many months), I realised that the UV from DE (I suspect the glass that came with the fixture is not anti UV) is so high that it is bad for the corals that is directly under its focus. The situation only improved when Orgasbt gave me a UV shield. Now I can see the damaged portions (directly below the MH) begin to recover, albeit slowly

That is the reason for the change to 250w SE. So I will start from 15inch and finish at 12inch over a 2 weeks period.

Thank you once again.

[Tanzy]

You could either acclimatise using short photoperiods and slowly increasing the duration. Alternative will be to use something that will reduce the intensity of light reaching the tank. For example, netting, many layers of glass or filters which are slowly removed.

Generally, I don't have problems acclimatising acros to new light bulbs with the photoperiod method.

[LinkinPark]

Thank you, Tanzy. Appreciate your advice.

Will go thru all the methods and choose the appropriate plan when the MH arrives.