Glass Top or Not? evaporation concerns

[earlybird]

Will I need a glass top for my 29g? I don't think I'm going to need to worry about fish jumping out based on my stock list as of right now but am thinking about evaporation. A glass top would probably slow my evaporation rate. I don't plan on having an auto top off right away (maybe down the road a little). With a sump/fuge how much evaporation can I expect on a daily basis with coralife flouros not MH?

 

[cveverly]

Personally I would not use a glass top. They tend to cloud up and seal the tank up too much. For comparison, I add about 1 gallon a day to my 120 and my 75. I would guess your 29 would evaporate about 1/2 a gallon per day.

 

[fishy7]

Cvev is right, they do cloud over.
Weigh -- costs and time.
I add 2 gallons a day in the winter and about 4 gallons in the summer for a 215. I have glass tops and use them for evaporation, airborn debrie, lights are 3" off the water and just overall safety. I leave one of them propped open for gas exchange.

When I do a water change, I take the lids off and give them a quick scub and things are back to normal.

All systmes are different. :thinking:

 

[earlybird]

Thanks. I'll probably go with one b/c of debris in the air. I may just get a piece of glass cut or have some holes drilled so it doesn't cover the entire top. Thanks

 

[cj7eagle]

I have mine open to make sure i dont have a problem with gas exchange, though with these lights, it does seem to evaporate like crazy compared to having a regular fluorescent and a hood. I wouldnt say a half gallon a day though.

 

[hagfish]

Most don't use glass covers. It prevents oxygen exchange. It traps heat. Powerful lights can heat them up and cause them to crack. They will get dirty and block light.
It's not really that hard to top off just a little every day or two.

 

[earlybird]

Jai what are you doing on the cpu? You should be working on your fuge j/k. I want pictures when you're done.

 

[watson3]

I use glass tops on a 55, and they do cloud up, but thats stuff i would want it to catch before it gets to my lights, and vice verso...See what i am saying..yeah it takes two minutes to rinse it off while i do weekly water, but id say worth it

 

[cj7eagle]

Originally Posted by earlybird

Jai what are you doing on the cpu? You should be working on your fuge j/k. I want pictures when you're done.
ha, actually just getting ready to start on it. do have to run out to home depot.... again... ahhh. luckily its less than 10 minutes away.
I will get the girlfriend to take some pics tonight when she gets home, as her camera is much nicer than mine.

 

[mandarin w]

I keep seeing so many concerned about evaporation, like it is a bad thing. Evaporation is a very good thing, very important and very healthy thing. Your tank needs to sweat, (evaporate) to stay healthy. Just as you need to sweat. On a very hot day if you could not sweat,you would suffer heat stress or even worse. Same thing with your tanks. That evaporation let the tank release built up gasses and helps it to cool itself. It is very important not to stop this. It the tank can not release the gasses and heat, it will be disasterous for your tank.
We are dealing with saltwater now, and alot of the freshwater rules do not apply anymore.

 

[hagfish]

Like Mandarin says, this isn't about how often you have to top off or how often you have to clean your glass on your light covers, or anything superficial like that. It's about gas exchange (getting oxygen into the water and letting some bad gasses out), and heat reduction mostly. Without the gas exchange, your PH is going to drop. And it really does make a big difference. PH can be effected by something as small as someone opening a window in the house for a while. There is really no good reason to use a cover. And if you think you have one, list it and I will tell you a way around your reason.

 

[uberlink]

I stopped using glass tops on my 28 gallon bow, and I've never regretted it. I ultimately did get an auto top off system on there, which was by far the best thing I ever did for the tank. If interested, I can tell you of an online source where complete top-off systems can be had very inexpensively. You'll never regret it. Particularly on a smaller tank, the salinity fluctuates more than you'd ever guess. Not unheard of for mine to go from 1.025 to 1.027 in just a day or so.

 

[anthonym28]

Read this article
http://reefkeeping.com/issues/2005-08/eb/index.php

 

[cveverly]

I have to agree with hagfish and mandarin w. Heat and gas exchange are the two big reason why I don't have a top. I even blow a fan across the surface of the water 24/7. I can not prove it but I think that is what helps keep my PH up in the winter. Living in Ohio and in a well built tight house I was having low PH issues in the winter. Now my PH is stable in my reef and FOWLR. Coincidence? … Maybe.

 

[earlybird]

Originally Posted by mandarin w
I keep seeing so many concerned about evaporation, like it is a bad thing. Evaporation is a very good thing, very important and very healthy thing. Your tank needs to sweat, (evaporate) to stay healthy. Just as you need to sweat. On a very hot day if you could not sweat,you would suffer heat stress or even worse. Same thing with your tanks. That evaporation let the tank release built up gasses and helps it to cool itself. It is very important not to stop this. It the tank can not release the gasses and heat, it will be disasterous for your tank.
We are dealing with saltwater now, and alot of the freshwater rules do not apply anymore.
You've convinced me. Makes sense. I'm learning a lot on this forum. My first thought was about the rise of SG. My second thought was how much RO water should I have laying around since I am planning on buying it. I didn't even consider that evaporation could be a good thing.

 

[mandarin w]

You will learn in time how much your tank usally evaporates. I will be a bit more in the summer with warmer weather. I would start off with 10 gallons for top off. (Just to make sure there is enough) Then once a day just add a little water to top it off. This way your salinity doesn't change to much. After a few weeks you will see if you use 5gallons or 7 gallons a week. But I would always keep an extra gallon or two around in case.

 

[ugluk]

Newbie here looking to start up a tank. So if I do not put a cover on my tank am I just supposed to lie my lights on top of the tank? If so should I have my water level a couple of inches below the top? How do I know what kinds of fish are jumpers and which arent?

 

[rainmaker6]

What about salt creep? Would it build on the bulbs?

 

[mandarin w]

Originally Posted by ugluk
Newbie here looking to start up a tank. So if I do not put a cover on my tank am I just supposed to lie my lights on top of the tank? If so should I have my water level a couple of inches below the top? How do I know what kinds of fish are jumpers and which arent?
Even with glass on top of your tank, you would not want to have your lights sit right on top of your tank. Ever sit by a window on a sunny winter day. It may be 25 degrees outside, the the sun shineing through the window you would think it was a nice spring day. The glass will intensify the heat from the light and heat up your tank quickly. Also the glass cuts out alot of the UV's from your light so your tank won't receive the full benifit of your lights. Two more reasons to get the glass tops off the tanks.
Most of the light systems come with legs so the lights will sit about 4-6 inches above the tank. This is high enough for the gasses to escape the tank. And a fan to blow across the top of the tank if needed.
As far a salt creep on the lights, Just make it part of your weekly maintanence routine to wipe down the lights. No biggy, just takes a minute.
If you are concerned that you may have jumpers in the tank, Then just use eggcrate, to cover the top of the tank. You have seen it talked about several time here. You can find this at almost any hardware store. they come in 2x4 sheets for around $10 depending where you go. You will find it in the lighting section. They are known as light defusers. As far as blocking the light out as asked in one of the other threads. I don't think they block out much light. Not enough to make a difference, as you can see in this picture.

as for eggcrate, that is the white stuff on top of the tank.

And as you see, I've mounted a fan to blow across the top of the tank. It helps with evaporation, and helps keep the heat out of the tank.

 

[ugluk]

Thanks for the help. I have lights already but no legs came with them. Is there any place I could purchase them? I never noticed them for sale in my LFS.