Why top cover glass is good

A while ago I was bashed for using top cover glass plates on all my aquariums. It was said they block lots of light penetration (18%) if 3mm thick, that they get dirty and hence need regular cleaning, causes heat issues and who knows what else.

While most of that is true, there is one benefit of using those glass covers that outweighs all of the negatives mentioned above - by a far margin. That is why I am today truly happy I kept the cover glass on.

See, at 06:00 this morning I heard what sounded like a burglar breaking in my house through the living room window. A very loud shattering noise sounded through the house. After investigation, I found that the one cover plate of my Sfigoli Infinity light pendant's 400W SE MH shattered to a thousand pieces, and all landed on top of the aquarium's cover glass. Had that cover glass not been there, I'd have to find 1000 invisible pieces of glass all through my tank - an impossible task.

 

wow

i am new in this hobby so i have many stupid questions like this one - how ofter do globes (be it T5, 8, MH, etc) blow like yours did?

 

My globe did not blow. The cover plate did. Not often. First I have ever seen.

 

that must have been some serious heat and a manufacturing fault on the cover plate

 

Most probably. The heat was only from the bulb, so my guess is a manufacturing fault.

 

Hi LikesFish - I share you pain brother - happened to my one 150watt metal halide. I am still seeing (and picking) glass from my aquarium substrate. Luckily did I not have ANY effects on the life-stock in my tank, due to this happening. BUT - I do not/did not have a glass-cover-plate on my tank (had one - LONG time ago - was also shattered by the Metal Halide heat)....

Metal Halides are DANGEROUS - the heat they produce can do a LOT of damage if one is not careful!

 

Yup I guess that is the other point of this post. Be careful with MH's.

 

Sorry to hear i will have to be carefull with my new light unit,thanks again for the best light unit around thumbs up for giesman

 

Yup that gieseman is really a piece of work. Loved it.

 

Few pros for coverglass but many negatives, let your reef be exposed to the air IMO

 

Name me one negative? Between my skimmer, overflow chamber and sump I have more than enough aeration. O2 saturation levels are always close to or exceeding 100%. Light penetration is more than adequate - I have 1000W of lighting through a thin cover glass panel - loosing maximum of 180W, which means 820W is still reaching the tank. The MH is far enough from the cover panel that there are absolutely no heat issues.

The chance for things dropping in to the tank and things jumping out of the tank (read: eels, wrasses) are just far too high. Many people follow the heat/light reduction/oxygenation thing blindly and forget that 99% of all people who have open tops have lost at some stage or another, a fish from jumping, and have most probably experienced something dropping in to the tank that should not have.

I value my livestock's health above spending 18% more on lighting to get through the glass.

 

Well for a start you are paying eskom to heat up or remove light from the use of a coverglass which is as you say 180w of light wasted.
Your evaporation rates must be low which limits the amount of possible kalk additions, more is better not less.
In my 12 years of keeping fish i`ve had 2 jump and become biltong and my tank has no bracing never mind a ceiling.
Do as you wish but thats what a forum is all about, sharing opinions.

 

I am not advocating that one must use cover glass - I am merely suggesting that there are viable benefits to using them, and this morning it saved my butt.

 

Then we are on the same page

 

Another great plus for coverglass is that it facilitates the running of a carlson surge device. No worries bout popping bubbles on to my halides. (se globes not shielded)When my surge kicks, the water rises enough to wash salt spray off my cover glass. Have to agree with likes fish about DO levels, with a open sump and overflow, DO levels are nothing to be concerned about, unless you have a huge bioload.

 

Hi likes had the unit on today i must say excellent light