Glass Top or Not?

[acers]

Hello Everyone.

I almost have my AP24 Gal all set up.  One of my final debates is should i have a glass top on or not.  Aside from the standard or needing to clean the glass everyweek what do you folks thing about heat, evaporation and the need for a glass top in general.

thanks ahead of time for the info

[Rybren]

Very few people keep a glass top on their SW tanks.  It traps heat, reduces evaporation, and blocks air exchange.  If you'll be doing a fish-only tank with no corals and low-intensity lighting, you might get away with a top.  Otherwise, topless is the way to go.

[Hookup]

In addition to Ryben's points, i'm always concerned about quality of light.  We pay for highly engineered lighting that outputs a very specific spectrum... I believe that when that light goes through a piece of glass, you'll modify the properties of the light, and thus, degrade what you've paid for, and more importantly, messed with what your corals need.

[Vincenzo.]

pendants/legged lights FTW. i have never used a lid on any of my tanks either. the pod comes stock with a lid. all i worry about is fish jumping.

[acers]

Thanks for the input.

I have pretty much decided that I will ditch the glass.  I will need to look into an ATO next i guess

Acers

[C-Dog]

I believe that when that light goes through a piece of glass, you'll modify the properties of the ligh

so do you think the glass or plastic that comes on the fixtures alter the properties of the light?

[Hookup]

Yep, i do... but I'm not 100% sure... i.e. no scientific fact here... I do assume that anything that Light passes thru effects the spectrum & intensity of the light... simply electron loss going through a media does this, even through air, water, etc... so why not glass.. given glass is a solid I believe that it has an effect...

The question is, is it an significant effect...  To that I do not have any answers, though someone with a PAR meter could easily test the drop in PAR by insterting a piece of glass... it'd be one indicator.

Air exchange is another important factor, which was mentioned above by Ryben.  If you're worried about fish jumping, which most of us are, then look into leaf protector/covers for ponds.  Typically this material has 1/8 to 1/4 inch grid of high density material that can withstand the heat of metalhalides.  if I didn't have a PITA corner bow I'd be using it myself.

[mikerobart]

Yah glass is not really a good option on salt tanks... just causes too many problems. An ATO a lot cheaper than a chiller that is for sure  . Might be able to find something good used here for ATO.. lots of good options, also easy to DIY with float switches. Melevsreef has a good easy diy. I got mine from autotopoff.com ( I can be lazy with diy at times), very happy with the unit.

[Jean L]

I have a smple Coralife CF and I broke the plastic sheet/shield trying to removed it so I could clean it. Havnt replaced it and dont think I will.
The light seems to be slightly better.
my 2c.   
J