Thoughts on open top vs. glass top

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7Enigma

Aquarium Advice Addict
Joined
Dec 29, 2005
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Havertown, PA
So I'm in a quandry right now. I would love to have the open top look, but have concerns about 3 main things:

1. temp issues straining the heater. My house in the winter stays at night around 55-65 and I have concerns that with an open top the greatly increased evaporation would cause the temp to drop or at least strain the heater enough to be problematic.

2. CO2 outgassing. The added evaporation and uncovered top I would assume would allow for much more CO2 to be lost. I have pressurized so it would seem to be just a cost issue (bottle running out sooner).

3. Potential electrocution hazard. I know everyone is supposed to turn off the hood light when doing maintainence but I never do (and probably most of us don't). I need to see in there! At least with the glass top you would have to seriously do something bad to have the light fall in, but with an open top it would seem to be much easier (just a couple small legs).

OK, sway me! :D
 
This is a question I was about to post also 7Enigma! Here is what I have concluded so far. I currently am running an open-top 75 gallon and have noticed some large issues with #1. It's the hottest part of the year (110+ here in Kansas) so we have our air conditioner running. The tank sits approximately 3 feet from an air vent. We have the house cooled to about 68 degrees. I have my heater turned on at 80 degrees and my tank still won't surpass 75 degrees temp. It's really irritating me and is causing me to think about buying the All Glass versa-top for my tank. I love the looks of the open top but am beginning to feel that for this sole reason it may be more hassle than it's worth. If anyone feels I should not see this much of a deficiency in the temp please let me know as the heater appears to be working appropriately but it is kicking on about every 10 minutes and still not keeping the temperature in check.

I don't currently have co2 injection yet so unsure on #2.

Also on #3 I am with you...I never turn off the light when doing maintenance. Oops! :)
 
Along with the three issues you point out, which I agree with wholeheartedly, here are a couple more:

1 - Livestock jumping, crawling or falling out of the tank.
2 - Covers give you extra space to lay equipment/tools. I personally hate holding onto scissors while pruning.

I seriously doubt a tank can be maintained with the lights off. :)
 
benefits:

More light gets into the tank.

Better gas exchange.

Some plants like to grow up and outside of the tank.
 
All of my tanks are topless except for the aquatech hex. I did have to put eggcrate on one for a few months to deter the cat from "fishing" in my 20, but the top is back off now. I think it is a much cleaner look, easier to work in and the plants look cool when they grow out of the top. I also can see the lilypads and red root floaters easier.
 
I do not use tops. I think the tanks look much better without them. I do agree more light gets in the tank that way. I have never had a jumper and my cat doesn't care about the tanks.

I always leave the light on when do I tank maintenance.
 
I now run all my tanks open top. I agree with all the concerns mentioned. I have lost a few jumpers, not many though. Havn't been zapped yet! Legs on my light are pretty solid. No noticeable C02 loss. I also have smalll kids to think about, I am fortunate enough to have a room dedicated to tanks, no one goes in there without me present. That alone solidified my decision to go all open top. Quite frankly, in this house nobody is really interested in my tanks! Along with the benefits rkilling1 mentions, I do it for ease of maintenance. I am always putting my hands in my tanks for one reason or another, just so much easier without the tops. For me it's worth it.
 
Does anyone have any idea what the difference is in the available light when a tank is uncovered vs covered. How much light are you losing with a cover?
 
A lot of that would depend on how clean you keep your glass. Mine got dirty fast and the water stains were tough to remove.
 
I should have put in my original post that the ONLY real reason why I was asking and would go with the open top was due to the lost light from the glass top (I've got pressurized CO2 and so don't want the increased gas transfer). I forget and neglect to clean the top of the glass (ceiling of the tank) for weeks or months at a time and am always shocked at how much junk has built up. My barbs will really go after floating food (tubifex worms, bloodworms, flake that doesn't sink, etc.) and normally will fly to the surface take a bite and immediately kick back down (causing a spray of water to hit the glass top which then dries). This buildup on top of my moderately hard water makes me wonder just how much light is actually getting down to the plants after a week or so.

Thanks everyone for your imput so far.
 
I run a couple open top tanks, they are the ones with pressurized CO2. I had more concerns about CO2 building up under the glass and reducing available O2. Than loss of CO2. With pressurized CO2 loss is easy to compensate for.

Some fish get startled at lights on, and can jump. My daughter was walking by the main tank (72g) a couple days ago and said "hey there is a fish on the floor". I went over, he wasn't dried out, so i plopped her back in (silver tip tetra). She was pretty messed up for an hour or so. I kept her a net, and put her in front of the filter outflow to get some water moving over her gills. She did recover and is doing fine now.

As for electrocution, well... I have dropped more than one light into a tank,m I have also broken heaters in there. Unplugged the item, and removed it. Electrocution is not a huge danger, unless you reach in to remove an item with power going to it. Also, fishy stuff should be plugged into a GFI plug or powerstrip.
 
As far as more outgassing of CO2, I don't think you'd notice the difference. I have a wood canopy on my tank which is open at the top and the back. I have DIY CO2 on a 55 and have had few problems.

Temp and evaporation...my tank evaporates A LOT because of the lights (2x96 watt). I've never had glass on this tank so I can't comment on how much less the tank would evaporate.

Is the outlet from the AC blowing over the top of the tank? That would certainly cause problems with evaporation. I do have some problems in the winter with my heater keeping up temps when the house gets cold but I think it's more that my heater is undersized for the tank. I do not have AC. Honestly I'd try and bump your AC up to 72 (or higher); it will take some of the stress off your heater and your electric bill!
 
zezmo said:
I run a couple open top tanks, they are the ones with pressurized CO2. I had more concerns about CO2 building up under the glass and reducing available O2. Than loss of CO2. With pressurized CO2 loss is easy to compensate for.

I have a HOB filter and so gas exchange is not a factor (wish I had a canister, but its only a 20 gallon tank). I could see in your situation that it would be a concern.


newfound77951 said:
Is the outlet from the AC blowing over the top of the tank? That would certainly cause problems with evaporation. I do have some problems in the winter with my heater keeping up temps when the house gets cold but I think it's more that my heater is undersized for the tank. I do not have AC. Honestly I'd try and bump your AC up to 72 (or higher); it will take some of the stress off your heater and your electric bill!

I think you misunderstood my post. It's the winter months where the cold outdoor temps are making the heater work, not the summer where I have the AC on. My natural gas bill would skyrocket if I kept the whole house warmer for the tank, and I'm not putting a space heater in the room just to keep it warm! :)
 
I think you misunderstood my post
Yup, I did...it appears I was actually responding to the temp numbers in the first reply post, not your post....sorry about that! But yes, I have the same problem with my heater not keeping up with the cold in the winter (only when the temps in the house fall below 65).
 
newfound was replying to the problem I'm having with the open top configuration. No the AC vent is actually on the floor about 3 foot from the tank. I also have a vertical fan rotating on high in my room 24/7. Unsure if perhaps I have a bad heater or if, by chance, the digital thermometer I just got from the Drs is junk. I do have a strip thermometer on the front glass just above the substrate line and it reads about 77.

Sorry 7Enigma...not trying to hijack! I'm enjoying this post though too so thanks.
 
I have switched both of my tanks over to open-top in the past year and couldn't be happier. The light fixtures hang from the ceiling over both tanks and can be adjusted to the exact height that will provide the best light coverage. I can also retract them toward the ceiling to give me more room to work when it comes to time to do maintenance. Light intensity is noticeably better without the glass tops, clean or not. I've never had any jumpers *knocks on wood* and can't really think of any major disadvantages to having an open-top tank :)
 
I really don't have the option of an open top tank since I can't drop any lights from the ceiling (I live in an apartment and I doubt the manager would like the holes). I prefer using a top in any case to cut down on evaporation and keep fish from jumping out (that didn't stop a pearl gourami though that jumped out when I had the top open for maintenance).
 
smn723 said:
Sorry 7Enigma...not trying to hijack! I'm enjoying this post though too so thanks.

My mistake. :oops: There is no hijacking a thread as far as I'm concerned, as long as it has something to do with the topic. Most often it helps others and possibly the OP if its a related topic.

I am really getting a kick out of these replies because its basically what is going on in my head right now. Who's going to win I'm still not sure. But I have an old house with plaster walls so attaching something to the ceiling is NOT going to be happening. We were on vacation 2 weeks ago and came home to our curtains on the floor in the living room. Due to the extreme heat from a recent heatwave the bolts just ripped right out after having been in place for 3 1/2 years. I can't chance having my arms in the tank only to have the lights come crashing down into the tank and making me crispy!
 
Very true 7Enigma! Do you have mounting legs and a splash shield on your light? I guess I never really worry about my light falling into the tank. Don't know if that's a good or a bad thing. :)
 
smn723 said:
Very true 7Enigma! Do you have mounting legs and a splash shield on your light? I guess I never really worry about my light falling into the tank. Don't know if that's a good or a bad thing. :)
I have a Coralife 65w 24" light for my 20 gallon tank. It does not have legs but I know I can purchase them (or make my own). This fixture does have an acrylic shield on it......hmm...I'm wondering if since I have a glass top I don't need the shield? That might let more light through....thoughts?
 
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