MH upgrade

[DaveP]

If I upgrade from 135 watts of PC lighting to a 10k 250 watt MH pendant on a 54 corner, what are you guys photo period reccomendations for the transistion period? I keep lower to medium light corals and do not want to shock them. Does anyone have any reccomendations? Thanks Dave :?

[benelux]

Hello Dave,

Yes, in fact you have to be very carefull when you will fire up your MH bulbs. I dont know what type of bulbs you will use and in what kind of reflector but here's a adaptation period specific to a Giesemann 230plus 2x250w 10k + 2x24w PC 67 blue.

The system (120 G) was full of both stony and soft coral (mainly acropora's and bulb tips). When we switched, we recommend not to move any of the corals inside of the tank but rather put some clothing shield over the most sensitive coral or put a piece of glass over the tank with shadow created by piece of tapes on the glass. We raised the fixture 70 cm above the tank and leaved only 4 to 6 hours a day of MH illumination while PC illumination could stay open for 10 hours. This initial period was keept for 1 week. Then we lowered the fixture to it's recommended level wich was 30 cm above the tank and modified our artifical shadow accordignly. Photoperiod stayed the same for another week with increased period by the end of the second week. In the 3rd week, photoperiod was increase 6 to 8 hours a day with gradual removing of some of the shadows we created. After 4 weeks, Glass was removed but pieces of "bugs screen" were left over more sensitive or slower adapted corals. You start with 5 pieces of screen and you pull one sheet out each and every 2 days.

It's important to look at the colors of your corals. If you note that some of them are becoming too clear in color it's a bad sign. Could mean zooxanthellae are being expulsed. If they become darker it's generally Good news but it's not very nice. If they become too "Fluo" it could mean too much UV radiation are being absorb. If those events occurs, lift the light, lower the photoperiod or add some shadow aera.

Another thing to watch, dont worry if you dont see your coral expends as usual that probably mean they have enough of light exposure. A good sign that light is adequate is the thin little "wax film" coral will produce. It's important to wash it away if there's too much but it mean that metabolic activity is in full speed. (sometime speeds kill!) :?

Hope i am helping you!
Will try to post a pic's

[DaveP]

sounds easy enough! :mrgreen: thanks, Dave

[Zack]

Dave
I just did the same thing what I did was have my lighting lowered over time, can you do that? or can it only be in one spot

[DaveP]

yes zack, I will be able to lower the pendant. I plan on lowering it over time as suggested by benelux. If I keep a good eye out I should be fine......Thanks! Dave

[Irisservice]

any before and after photos?