New 150W MH 10,000K question

We just installed two 10,000K MH bulbs to our 90G tank and I have some questions. Before this we used 20,000K bulbs that were a little old and needed replaced. We chose to get 10,000k because we wanted to see more growth in our corals.

The tank looks much more yellow, even with two CF acintics. But is going from 20,000K MH to 10,000K MH too much of a shock for the coral?

I ask this because my big GSP isn't opening up today and the toadstool doesn't look as happy. The toadstool is opened, but not as large as he ususally is. The GSP are close to the top, probably 8 inches away from the light. Our fixture sits on top of the tank and is probably 5 or 7 inches away from the water.

Frogspawn, torch, hammer coral, and everything else looks ok. Do I just need to put the GSP on the bottom for now, and let the tank adjust to the new lighting?

 

Definitely acclimate the corals to the new bulb.

What brand of bulbs did you get?

 

I will have to go check. What do I need to do now? Only run the lights for a few hours today and let the acclimate? Are the corals in there now getting damaged by having new light and keeping them on for the normal 8-10 hours a day?

 

im not sure if the coral would react to a change in color temp, but 10lk is somewhat yellow and 20k is blue, you could always try from something in the middle? 14K, 12K? that would give you the inbetween look/

 

I would both move down the gsp for now and reduce the photo period. I just changed from 10k to 20k and it took at least 2 weeks to acclimated my corals and I still saw a slight shift in color.

You can try going to HD and getting some of their mesh screening as well and place it over the tank until the coral acclimate.

Plus if you changed from old stock bulbs to a newer type of brand it will be a significant change and warrent acclimation IMO.

 

Well our fixture is odyssey, and the bulbs we got are odyssey as well. My brother got them form aquatraders or something like that. I think my brother is going to reduce the time the lights are on, and have the MH on for only 4 hours. Then we will leave the acintics CF and single T8 10,000k bulb on for the full time. Then adjust the time on the MH a hour every week until we get them where we want them.

 

The PAR value of a 10000K bulb is significantly higher than a 20000K bulb. That is why they are reacting the way they are. 10000K simulates shallow water spectrum, whereas 20000K simulates wavelengths seen in deeper water, which is why it is blue to our eyes.