LEXAN ?

[Xtreme]

I just put a snowflake eel in my tank. I have lexan covers too keep eel in tank , i'm introducing two 250 metal halide to my tank . my ? is will the spectrum change with lids on. should i use 10k,20k for sps?

[GaryP]

You're putting an eel in an SPS tank? You might want to re-think that. The waste that a large predator produces is not typically compatible with SPS. They require the highest water quality of any coral.

As for the lights. My answer would be both. SPS will do OK with 10K but without something like 20K or actinic you are going to miss out on a lot of the color. The SPS will do better with both spectrums IMO.

I'm not sure about a spectrum shift on the Lexan. I'm sure that someone else can answer that question. However, any cover on a tank is going to decrease the amount of light reaching your corals, especially if you aren't diligent on keeping it clean.

Gary

[captexas]

How thick is the Lexan? Matt could probably give a better answer, but I think Lexan is a cheaper quality plastic. I don't think it will do very well with the heat of metal halides. My bet is that it will melt/start burning which in turn will release toxic fumes into the area. Also, having the top of the tank covered with halides will create a greenhouse effect causing the water temp to greatly increase. That and you will have to constantly clean the covers from salt creep.

[Yancey]

I have no idea about the toxicity of Lexan under heat, but lexan (aka, polycarbonate) is non toxic under normal usage conditions and when exposed to mild solvents. Lexan has a higher water percentage then acrylic and is much much much much much much stronger then even the best acrylics. It's also a joy to machine and drill holes into, where as drilling acrylic can be a nightmare. But the transparancy is on par with acrylic, but it does scratch just like it :-(. Good luck

[Xtreme]

You're putting an eel in an SPS tank? You might want to re-think that. The waste that a large predator produces is not typically compatible with SPS. They require the highest water quality of any coral. YOUR RIGHT they do put out a lot of waste. I went from 15% to 40% water changes a month. 420cal,8.2ph,3.5alk