glass top or not ?

[stangnet]

With my new tank I have the glass top on. When I get ready for MH and VHO's I haven't decided if I'm going to leave it on. I tried on my smaller tank for heat and gas exchange, but lost a fish from jumping out :( , so back on with the top. Advise ?

[BigE]

in about 3 years I've only had 1 fish and 1 shrimp jump out. The glass lid will block a lot of light and can inhibit fresh air from getting to the water surface.
Instead of the glass lid you could try using a vertical barrier on the side of the tank.
On my tank the hood acts as a barrier on the front and sides so I would only need one at the back.

[Mark Anderberg]

Listen to BigE, as he is wise 8)

[phistio]

personally i keep my cover on my tank...it helps slow evaporation...though i wouldn't have much problem with fish jumping out, as my canopy would keep
'em inside...

i don't notice too much light loss...but it is acrylic and allows 97% light to pass through it. just got to keep it clean, and clear of salt deposits...

[Reefer504]

No glass top on mine.

Just curios why would you want to slow evaporation,I thought it was a nature's way of cooling? :?

[phistio]

since i have a smaller volume tank (25 gallon) water loss is noticed rather quickly...and the way my tank is set up...(with an IFS) it's best for me to use my cover...

[fishfreek]

I have an open top on all my tanks. Freshwater and Saltwater. The reason is 2 fold.

1. as was stated above anything between the bulbs and the water reduces the light into the tank.

2. enhanced gas exchange. This was eluded to above by a member saying it slowed his evaporation. I want to enhance my gas exchange as much as possible so I have an open top.

My canopy is about 1' taller than the top of the tank and is enclosed on 3 sides leaving the back open for return lines and such.

My lights are about 5-7" above the water surface.

[Pineapple House]

I don't have any glass top on my tank, and so far none of my fish have ever tried jumping out.

One thing that has worked for many people, is to have a wire mesh across the top of the tank. This will prevent fish from jumping out, while giving a gas exchange. I would buy nice plywood, and cut it the size of your tank. Cut out the inside of the wood, leaving 1 inch around the outside. Buy how ever much mesh you need, and nail it to the wood. You can place this wood/mesh over your tank, and the canopy on top. I have not attempted to do this myself, but have seen many other people do this.

PH =)

[fishfreek]

OH.

Pineapple House your comment about the screen reminded me of another item that could be used.

Its called "egg crate" and it can be found in your home improvment store. Its basicly 1/2" squares in a plastic grid. Its sold as a florecet fixture light diffuser.

[Mark Anderberg]

I wonder if the egg crate would inhibit the concentrated light penetration into the tank? I'm not sure that diffusing the light or if this would diffuse the light in a negative manner :?:

[fishfreek]

I dont see how egg crate would diffuse light any more than wire mesh.

[ssgibby]

Actually, eggcrate is used as a light diffusers for offices.

[saltyfishboy]

If your system commonly has high nitrates you might not want to put a top on. Like mentioned above...it reduces gas exchange...which results in higher nitrates.

[Irisservice]

Well i cover only the back half just to reduce some evaration and loss of heat.When i removed all the glass my heater would not stop turning on$$$$$$. So now i just cover the back side and clean once a week. In the summer when its real hot week i remove all glass.

[david]

Before I upgraded to my 110 , I used glass lids on my 55 gal
That tank was up for 3 years, and had 200 watts of lighting.
I had to use a few fans to keep the lights cool, but I hate evaporation.
As for O2 exchange i had a skimmer on the back and a power head near the top.
there was just a 2" gap in the top between the hot skimmer and the aquaclear 300, everything else was sealed. If i recall i think i even tried to seal that 2".
I had to add about 1 gal of water a week or less, my 110 gal without a cover need's 1 gal a day.
I did need a small fan pointed at the tank in the summer to kep temps lower.

[fishfreek]

Irisservice,

You say if you take your top off your heater will not shut off. That sounds like to me that your heater is undersized for your tank/room temp combo.

You should size your heater based upon how much the tank temp has to be above room temp. So if you have to rase the tank temp 5 degress F above room temp you dont need as big a heater as if you had to rase the temp 10 degrees F.

I like to go with multiple heaters. I have 2 250W heaters on my 80 gal with a 30 gal sump. Durring the day 1 heater might flip on occasionally and in the AM with the lights off I might see both heaters on. My tank is in the basement where its usually in the high 60's and i keep my tanks at 84F fairly steady.

David,

Yes having a skimmer will greatly enhance your gas exchange. The evap you say you experence on your 110 at 1gal per day is acutally low. I have heard of some who experence 2-3gal per day evap.

[HoopsGuru]

I don't know of any glass top that completely cover the whole top of the tank. Most cover a large area and have the removable back strip to allow filters, etc. All it takes is one accidental splash onto a hot bulb to realize that it would be wise to have some form of cover on a tank. :wink:

Gas exchange with a glass top or without is really not a whole lot different. As long as you consistently break the water surface with current you have more than enough gas exchange as it takes relatively low amounts of oxygen to maintain the levels in a saltwater tank.

[Irisservice]

I did not mean that is stayed on contant. but turned on more offen than i wanted. Any thing to save on Electric!!

[Nemo]

I was just pondering the thought of whether I should go with or w/o a glass top and I was wondering if you need to break the surface of the water to increase gas exchange at the surface. And if so wouldnt the air bubbles from the PH and the skimmer create the same effect as leaving your tank uncovered ? IMHO I think that this would indeed be better a gas diffusion then just leaving your tank top off.


Lighting is another issue but I would think that as long as you dont mind cleaning your glass top then the lack of lighting shouldnt be a factor. If it is then you should think about increasing the lighting by adding another source of light. Just pondering the topic! :wink: