do DE halides burn corals?

[clown jr]

i have heard that the double ended halides emit harmful uv rays that can burn corals and inverts and that they need a glass shield. i recently purchased a 70w DE halide and the lfs guy said to use plexiglass to block out the harmful uv rays. my questions: do de halides burn and if so will plexiglass block the harmful rays?

 

[bang guy]

The UV from DE MH bulbs will damage the chromosomes of deeper water corals and prevent them from reproducing.
Acrylic will melt.
Regular glass will shater if it gets splashed.
I recommend Tempered Glass.

 

[viper_930]

I was going to replace my black center brace wil a clear acrylic piece. The DE halides won't melt this right? Because it is clear?

 

[montidanae]

it would still melt it, i dont see anything differnt with the black acrylic and the clear, they both will heat up and melt, only one will do it faster :notsure:

 

[viper_930]

When light hits something it will turn into thermal energy. So since the light passes right through clear acrylic (mostly) then it wouldn't heat up so much. I know it still will have some degree of heat, but not nearly as much as the black acrylic, right?

 

[flatzboy]

Originally posted by ViPeR_930
When light hits something it will turn into thermal energy. So since the light passes right through clear acrylic (mostly) then it wouldn't heat up so much. I know it still will have some degree of heat, but not nearly as much as the black acrylic, right?
Nope, from experience I had an acylic top on my old 20g. reef and I had my 110w pc light mounted on legs sitting over it 3'' and within a week it was all warped and messed up. How are planning to cut your cross brace off and put an acrylic one on? Also if you use one metal halide your gonna have one heck of a shadow were your cross brace is unless you figure out how to replace it with a piece of acrylic.

 

[viper_930]

Originally posted by FLATZBOY
Nope, from experience I had an acylic top on my old 20g. reef and I had my 110w pc light mounted on legs sitting over it 3'' and within a week it was all warped and messed up. How are planning to cut your cross brace off and put an acrylic one on?
The piece I have right now is on the hood on my lights (2x65w PC). It hasn't warped or anything. It barely even gets warm when the lights are on. I was going to mount it will screws and maybe some glue underneath the existing black brace, then cut the center portion of the black brace off. Also, I just checked again, and the piece of "acrylic" I was going to use seems to be plastic, same thing as the brace on the tank.

 

[viper_930]

How do other people with halides and center braces work things out? Just put the halides on the side?

 

[flatzboy]

On my 46g. bow front I have 2x175 watt metal halides one on each side of the race and 2x96 watt pc's for a supplement. Heres what I would do if I were you. I just buy a pfo 150 hqi pendant and mount it in your canopy so you don't have to worry about putting something in there to filter out the uv then I would add to vhos or 2 pcs and have bothe bulbs be 50/50 bulbs so you won't notice the brace.

 

[viper_930]

I'm just getting a 150w 10,000k HQI setup with 2x65 (1 actinic 1 50/50) watt PC lights. I already have the PC lights, so I can just buy the MH parts and add them to my hood. I already ordered a tempered glass for filtering the UV, it will be here tuesday. I really have no choice on what kind of MH parts to get, my mom is getting me if for my Bday, and so I had to find something cheap enough so she will cover the entire cost. I found a PFO magnetic m81 ballast, socket, and a hamilton HQI 10,000k bulb all for $150.
I'll just replace the center brace with the clear plastic peice I have now, and if I notice anything wrong, warping, anything of the sort I will shut down the MH lights and make some modifications. I will still have to acclimate my tank to the new lighting, so I will have the oppurtunity to monitor the whole setup and the center brace while I slowly raise the on time of the MH light. How does that sound?

 

[flatzboy]

That sounds pretty good then because you got the 2x65 watt pcs so you shouldn't really notice the cross brace.

 

[viper_930]

Cool, Thanks! :happyfish

 

[clown jr]

ok, i have the tempered glass coming late this week. can i use the plexiglass to start adjusting my tank to the halides? I have a well-cooled canopy i built myslef so im not worried so much about the heat as the corals being "burned" from the de halides. does plexi block the uv rays?

 

[clown jr]

another site says if you have a plexi lid and the halides are 6" or more away then its ok. is this true? i dont want to harm anything.