Glass top

[PaulK]

What was the difference in your PAR readings with and without the glass when it is clean? I wanted to cover my tank to slow evaporation as well. I only had 1/4 inch plate when I was checking par readings, but I thought it was blocking my light a little more than 10% even when it was clean. I could crank up my lights, but it is summer and I am not sure I want to deal with the heat they put out.

I can’t remember but I can test it when I do a water change this weekend. I don’t think it was much of a difference, just a few percent.

 

[vetteguy53081]

I think people exaggerate the negative effects of glass tops. I’ve run a glass top on my mixed reef for years. I had too much evaporation with just screens. Having a glass top cuts evaporation by at least half, maybe more. I feel like it also keeps out dust etc.

The only negative that I can think of is that you need to wipe it off every week or so. I tested with a par meter and it showed that after a week without cleaning the glass reduces light by about 10%. That’s more than a screen top, which only reduces PAR by a few percent. But I don’t run my LEDs at full power anyway so I didn’t care. Some people say the glass cover reduces gas exchange, but unless you have a tight seal I can’t see how that would happen.

Simple quick thought- notice most all pet stores use glass covers? Many advantageous reasons they do

 

[w2inc]

Simple quick thought- notice most all pet stores use glass covers? Many advantageous reasons they do

When I worked at a shop we kept covers on tanks for a few reasons.
To keep pennies out of the tanks
To keep hands out of tanks
To keep random things from falling in tanks
To keep fish from jumping from one tank to another
To stop evaporation, control mold in the shop, mange a comfortable less humid environment for employees and clients, less strain on ATO
Prevent theft
Prevent cross contamination.
Prevent damage from predictors to customers, liability issues.
We kept the tops off of the reef displays such as frag tanks so they were easier to look into.
Occasionally we opened the lids and ran fans when the shop was just too hot.

At home it is a different world. Most of those things are not an issue. I personally would like to control the humidity of my home and potential mold that grows in that environment. I would also like my DI resin to last a lot longer as they system tops off less.

 

[NY_Caveman]

When I worked at a shop we kept covers on tanks for a few reasons.
To keep pennies out of the tanks
To keep hands out of tanks
To keep random things from falling in tanks
To keep fish from jumping from one tank to another
To stop evaporation, control mold in the shop, mange a comfortable less humid environment for employees and clients, less strain on ATO
Prevent theft
Prevent cross contamination.
Prevent damage from predictors to customers, liability issues.
We kept the tops off of the reef displays such as frag tanks so they were easier to look into.
Occasionally we opened the lids and ran fans when the shop was just too hot.

At home it is a different world. Most of those things are not an issue. I personally would like to control the humidity of my home and potential mold that grows in that environment. I would also like my DI resin to last a lot longer as they system tops off less.

Great post.

Personally, I am an uncoordinated liabilty around glass (one of my biggest disasters was double glass shower doors $$$). I cannot imagine putting glass over or around glass intentionally. And having to go in and out of it all the time.

 

[vetteguy53081]

Great post.

Personally, I am an uncoordinated liabilty around glass (one of my biggest disasters was double glass shower doors $$$). I cannot imagine putting glass over or around glass intentionally. And having to go in and out of it all the time.

I have a gap for feeding and air release by discharge for exchange if gases. Been using glass for over 30 years

 

[PaulK]

What was the difference in your PAR readings with and without the glass when it is clean? I wanted to cover my tank to slow evaporation as well. I only had 1/4 inch plate when I was checking par readings, but I thought it was blocking my light a little more than 10% even when it was clean. I could crank up my lights, but it is summer and I am not sure I want to deal with the heat they put out.

So I just measured it. My glass doesn’t seem to block much light at all. With glass that hadn’t been cleaned in two weeks, I was getting about 10% par loss. After I cleaned it, I was getting only 4% loss. I measured this by putting the meter right under the glass, above the water surface and directly under the LED fixture. I went from 780 par without glass to 749 with clean glass to 700ish with dirty glass. This is just standard 1/4” plate glass.

 

[PaulK]

Actually if you google light loss through glass, it seems like something around 4-6% is standard. So I guess my measurements were accurate.

 

[Pedal Dangit]

I'm glad to have found this thread. I'm thinking of running glass tops on my tanks. Mostly for evaporation, but also to keep the dust and dog hair out as best as possible. I hate to admit this, but I occasionally find a neglected corner of my house and I find some fairly large dog hair dust bunnies. I think, if that much crap has accumulated in just a few months of not cleaning the hardwood floor, then I can only imagine how much actually gets filtered out of the house by an open 120 gallon aquarium and 50 gallons of sump over time. I mean if you are not removing it with filter socks... it is just accumulating in the system. Right? The skimmer I guess removes some of it? Maybe it is a not an issue to be worried about? However, my daughters bathroom proximity next the tank is a issue I worry about for hair spray, perfume, etc.

 

[w2inc]

So I just measured it. My glass doesn’t seem to block much light at all. With glass that hadn’t been cleaned in two weeks, I was getting about 10% par loss. After I cleaned it, I was getting only 4% loss. I measured this by putting the meter right under the glass, above the water surface and directly under the LED fixture. I went from 780 par without glass to 749 with clean glass to 700ish with dirty glass. This is just standard 1/4” plate glass.

Thanks for doing that.

 

[Pedal Dangit]

Personally, I am an uncoordinated liabilty around glass (one of my biggest disasters was double glass shower doors $$$). I cannot imagine putting glass over or around glass intentionally. And having to go in and out of it all the time.

Legit concern. I already chipped one of the 4 foot long top pieces just moving my tank. I wish they were split into 2 foot long with a divider. The only downfall of the top I see is the increased maintenance of cleaning them every week.