Want to make lighting dimmer.

[kimbowee]

I have a 20 & 30 gal tank that I would like to make a bit dimmer for the fish. Both have glass on the hood supporting the light strip. I use a 15watt flouresent sp? bulb for the 20 gal & a 20 watt flouesent for the 30gal. Is there some kind of material or fish safe paint I can use on the glass that would make it somewhat dimmer? There are no real plants in either tank. I don't want to completely black it out.

Am not sure if this would affect the fish or not. The 20 gal has guppies, a molly and oto's. The 30 gal has Gouramies, Hatchetfish & upside down cats.

Thanks bunches!

 

[Lateral Line]

This is an unusual question. The opposite is usually the case, how to get more light in the tank.

Okay, well I assume you have your reasons, although I can't imagine what they might be. All the fish you mention are at home naturally in brightly lit wawters.

I would think a simple water based emulsion paint would be okay. It will not "wet" the glass very well therefore not totally block the light like say an oil based paint.

Fluorescent lamps do not get really hot, but are warm enough to generally prevent condensation forming on them and thus dripping into the tank.

 

[Barry P]

The problem with waterbased paints on the bulb is that it will eventually burn off and could drop into the tank.Even if its waterbased it would most definitely not be good for the fish. You could invest in a Blue Moon Bulb or alternatively you could buy some blue coloured paper (Transparency Paper) and find some way of blocking the light with this...?

 

[CFC]

I understand your problem, the curse of being a catfish lover means your tanks need to be dark and gloomy What i usually do is use a tube that is much smaller than recomended for the tank size, for example i have a single 3 foot tube over a 200 gallon tank, but if this is not a option for you then wrapping tinfoil around the tube and securing it in place with electrical tape leaving just a few gaps for the light to come through will give the desired effect, i used to do this on my juwel tanks and it worked well.

 

[kimbowee]

Thanks for the advice everyone. Think I am going to try the tinfoil method. This seems to be safer then any other way. With painting I am afraid the fumes may bother the tank.

I have fake floating plants in the tank and all the fish congregate to the area where the floating plants are. I have been researching this and all of the fish in the 30 gal prefer dimmer lighting. With all the fish pretty much hanging out on one side of the tank it looks pretty unbalanced. All are very active when the tank light is out but room lights are on and are all over the tank.

When the tank lights are on the UDC's will not come out of their caves. I have been feeding with tank lights off & the UDC's will actually come eat out of my hand. The Gouramies and hatchetfish seems to love it too.

I want as natural as an environment for the fish as possible. From what I have been reading both the Gourami and Hatchetfish come from water with thick vegetation therefore limiting the light. And of course, my cats, we all know where they like to hang out!

Thanks again for the ideas!

 

[Lateral Line]

>>> will eventually burn off and drop into the tank

I doubt a fluorescent lamp would get hot enough for that. I'm not really sure it would do much harm if it did. Water based paints tend to release their emulsifiers as they dry. What tends to be left is a dried caking of pigment, which with white paint is usually Titanium Dioxide which is inert.

>>> Hatchetfish come from water with thick vegetation

Whenever I have seen hatchet species in the wild, they have been in fairly shallow water, (less then ½m), with some roots and a bit of floating gunk, but never really enough to create shade. Of course, the water is very dark coloured, but they are so close to the surface, that doesn't really enter into it.

Gouramies as well I've seen in fully open to the sun paddies, ditches and drains.

The other methods described here would be just as good if you don't want to use paint.

 

[vincebeach]

One option to consider if you want to dim flourescent light fixtures is to use a dimmer switch that is specifically made for flourescent fixtures. You can not use a regular incandescent dimmer on flourescent fixtures. I have been an electrical contractor for about thirty years so I know about lights, but just beginning to learn about aqauriums.

 

[SkiFletch]

if you have a clear acrylic cover over the tank and the aluminum trick doesnt work, you could also try a couple sheets of wax paper over the top of the tank lid... That might dull out the light enough

 

[Lateral Line]

@VinceBeach:

Do you know exactly how fluorescent dimmers work? I am aware of how a fluorescent lamp works, (i.e. the phosphors on the inner sleeve wall fluoresce in response to the higher energy em radiation from the ionised carrier gas/plasma discharge).

I'd of thought that if you reduce the carrier levels to produce less exciting energy for the phosphor, there would quickly come a threshold below which the lamp would cease to operate.

Another approach I considered was pulsing the discharge, and varying the pulse characteristics. That, I would have thought though, would drastically shorten the life of the lamp by corroding the end electrodes.

 

[kimbowee]

LOL. I am no good with electrics. Not looking to start a fire. You lost me with the first sentence. )

I tried the tinfoil method yesterday and all seems to be going well. The fish seem alot happier. The UDC's were out all last night and the rest of the fish are no longer hanging in one spot in the shade. The hatchetfish were happily playing in the filter flow. If I see any problems I have a spare tank, so I can switch my stock around if need be.

Thanks again everyone!

 

[vincebeach]

@VinceBeach:

Do you know exactly how fluorescent dimmers work? I am aware of how a fluorescent lamp works, (i.e. the phosphors on the inner sleeve wall fluoresce in response to the higher energy em radiation from the ionised carrier gas/plasma discharge).

I'd of thought that if you reduce the carrier levels to produce less exciting energy for the phosphor, there would quickly come a threshold below which the lamp would cease to operate.

Another approach I considered was pulsing the discharge, and varying the pulse characteristics. That, I would have thought though, would drastically shorten the life of the lamp by corroding the end electrodes.

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I am not sure exactly how the flouescent dimmers work but I have installed them in the past. They most likely vary the voltage output of the ballast or transformer that powers the flourecent lamp.

 

[Bloo]

Not a clue if something like this will help of give ideas at all, but I came across this item on eBay

 

[Lateral Line]

That eBay lamp with a dimmer is not a fluorescent. It just looks like one! It is a normal tungsten filament lamp with a single long filament along the centre of the glass tube. It has a single contact at each end and can be used with an ordinary incandescent dimmer switch.

 

[BigC]

Why not use surface plants, a more natural way to lower the lighting levels and it has a more calming infulence on the fish.

 

[Bloo]

That eBay lamp with a dimmer is not a fluorescent. It just looks like one! It is a normal tungsten filament lamp with a single long filament along the centre of the glass tube. It has a single contact at each end and can be used with an ordinary incandescent dimmer switch.

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oh it said fishtank so I thought it might fit the bill or give an idea - but obviously not