too much light?

[mhills16]

I have a 250 watt MH, with brand new ph.14k bulb...and i only have the fixture 7 inches above the water and majority of my sps only a few inches from the top of the water, is this too much lighting? sometimes i notice that after a few hours of the lighting being on, they produce thier slime, but, they have great color and seem to be growing well...they dont have polyps extended after a few hours with the lighting on... I cant really move the light though..so...any ideas, or, is it fine...mike

 

[mixer911]

how many hours is the light running Mike? How long have the corals been in your setup under that lighting? How old was the bulb that was replaced?

7" should be ok otherwise.

 

[mhills16]

around 5 to 7 hours a day constant lighting, the old bulb was well over a year old id guess....I really dont know, i got it used the fixture , and had it for a long time before using it..The sps have been in there for around a month or so, they are doing good, I just notice they dont like it after like 2 hours of constant lighting...I just put a red cap in there the other day, it was bright red and now i notice it getting a bit darker of a red color...But the rest that have been in there the longest are doing fine..I think maybe after about 2 hours being so close it might spike the surface temp of the water maybe....i dont know, maybe i'll get another koralia, so ill have 3 directly going towards the top center.

 

[mixer911]

If the old bulb was over a year old the PAR could have been really low. The New bulb is going to have a higher PAR so it could be that they are getting more light than they are used to. I would cut the light back a couple hours and then over the next few weeks add 1 HR a week or so.

Heat also could be an issue in your case too.

 

[commonstranger]

Rick is telling you right here Mike. I would do what he's saying and see how it goes. I would also check the temp too after the lights have been on about 3hrs and see how its affecting the tank. A good temp change will **** everything off good.

 

[andywe]

Speaking of Temp, it has been cold enough that my tank is varrying almsot 2 degrees at night now. I am going to have to add another heater for this cold weather! If temp is varrying and it is ok when the lights are on, then you might look at whether you have enough heating for night time.

 

[sandalscout]

Speaking of Temp, it has been cold enough that my tank is varrying almsot 2 degrees at night now. I am going to have to add another heater for this cold weather! If temp is varrying and it is ok when the lights are on, then you might look at whether you have enough heating for night time.

I was having that problem as well, but mainly due to the fact that our gas heat was dead for 5 nights! Once I got my RKL hooked up, I felt a bit more control with the heaters and cranked them up 3 degrees each, that helped a TON, when set at 81, they weren't getting above 78. I hate the variances in heaters some times.

 

[mhills16]

good point, I have a 3 degree temp change at night, but i figured it didnt matter because in nature the temp varies at night too correct?? Anywyas, they all look healthy, and i only do 2 hours MH on several times daily now...seems to be working..thanks, Mike