Too much light?

[flyin2jz]

just wondering if anyone has seen this before. I have a 215 gallon tank that is only around 16in high and 3ft wide and 6ft long. I have 3 250w radiums on the tank with reflectors. I have been having issues with my sps going whiter and whiter till they die. I have never had this issue but it seems to be getting worse. I did 3 water changes of 33 gallons in the last 2 weeks. I have zero polyp extension even at night now. Some sps for who knows why arent turning white. A blue tort frag is as bright as ever and a ice tort look great with deep colors. All the rest are slowly getting whiter by the day. No phosphates,nitrates,nitrites or ammonia. My calcium is 500 and alk is around 7 checked yesterday. I am beginning to think the lights are too much over such a shallow tank. Is there a chance of this? i have zero coralline in the main tank except where its shaded in the overflow and its full of it. I really cant raise the lights up higher because its in the kitchen and cant put the radiation all over the kitchen table. Im wondering what i should do. I can get ballasts that are changable and will fire a 250 watt bulb and lower it to 175 and it will stay lit just be less intense. My buddy has these ballasts and you can change watts and from hqi to regular and it will lower the output. Any ideas on what i should do. Im starting to trip out. I have at least 20 ora frags in the tank that are looking terrible...please help.

 

[mike_cmu04]

It could be too much how high are the bulbs off the water and do you acclimate the corals to the light. More likely though you have some kind of pest that is killing them

 

[flyin2jz]

they are about 10 in off the water level. I have these issues as soon as i put a coral in the tank. Surely it would take longer than 3-4 days if it was a pest. THey look good for about a day then start whitening daily after that. I cant see the lighting causing it because im only running 250s. The coralline algae issue is bothering me too. I dont get why it wont grow in the display tank.

 

[cindre2000]

Lack of coraline growth points to too much light. Coraline algae actually grows best in moderate light, not high light. I am getting good SPS growth in the top half of my 120g under 150w halides.

I would drop everything onto the sand bed if its not already there and then put egg crate over the top to reduce the light level even more. I personally would not go over 175w for that depth of tank. In fact I had a 175w w/ basic reflector over my 16" deep 30g cube and got great SPS growth w/ a 20K bulb.

 

[CUNAReefer]

If you have spent that much on ORA Frags, why not get yourself a lux or par meter. You would at least be able to confirm or rule out the light. Dana Riddle has some great articles on light saturation points for SPS corals.

 

[huskysglare1]

250w on a 16" tank and only 10" off the water? that's a lot of light.

 

[flyin2jz]

I'M gonna egg crate and screen tonight and see if it helps. I believe the corals that look good want alot of light and the others it's just too much. I also believe I'm shocking all my new additions. These corals I'm getting look great until they enter my tank then no pe and the color quickly turns white. Is screening effective in lowering the light?

 

[neoalchemist74]

Screening is very effective, you can use multi layers and remove layers until you get where you want, but you might want to try cutting your lighting down down to a few hours a day first.

 

[Alex T.]

Honestly, it's not necessarily a lot of light. What does it matter if the tank is only 16" deep? Many people have 400 watt bulbs with sps corals closer to the light source than 16". If you're growing sps and clams on the sandbed, you're fine. Lower your photoperiod if you notice adverse effects.

 

[MrKite24]

Screening is very effective, you can use multi layers and remove layers until you get where you want, but you might want to try cutting your lighting down down to a few hours a day first.

That is a good point. How long are the lights on each day? Also what are your Mg levels? I've noticed that coralline loves Mg.

 

[flyin2jz]

It's not a mag level issue. It grows in the overflow like crazy where it's shaded. Also grows in the sump under a 40w actinic bulb. I just tested nitrates last night and they were like 20 so that's a bit high. I thought nitrates caused corals to brown not lighten. L