Reducing Light With Polyethelyne Wrap

[Django]

I have some algae in the tank that seemed to be growing rather fast, and I want to reduce the light a little, so I'm trying a layer of polyethelene wrap on my glass cover. I hope it works. I am running a 10g with 2 10-watt compact fluorescent lights (CFL) in dome reflectors sitting on the glass cover on top of the tank.

I'm a little concerned about the wrap filtering out some light used by plants, so if anyone knows about that please let me know.

[Django]

I found this sentence about the thickness of plastic wrap:

"Common plastic wrap is roughly 0.5 mils, or 12.5 µm, thick."

This would have a bearing on how much light goes through.







http://en.wikipedia.org/wiki/Plastic_wrap

[Kathyy]

I would be worried about the plastic getting melted by the heat of the light bulbs more than anything. Would putting it under the glass cover be safer?

Could you find a scrap of window screen to use instead? Works great and withstands a lot of heat.

Somebody here put a layer of cheese cloth down to shade the tank.

I guess a solid sheet could remove certain parts of the spectrum more than others but I think you are fine with a clear film.

What is the length of time the lights are on? Perhaps you could reduce it to about 8 hours.

[el Caspar]

I would try leaving my lights off for longer first. You could pull a bulb or drop your 10ws for something less. A lot of ppl have their lights on 12hrs a day. Usually it's way too much. Dropping to 10 or 8 hours would make a difference.

[Django]

Originally Posted by el Caspar

I would try leaving my lights off for longer first. You could pull a bulb or drop your 10ws for something less. A lot of ppl have their lights on 12hrs a day. Usually it's way too much. Dropping to 10 or 8 hours would make a difference.

My lights were on 10 hours a day and now are 8. Funny thing - I don't want to get stuck at a photoperiod of 6 where I can never look at the aquarium at all

[Jules]

Just get some greenhouse shade fabric - that will do the job much better than poly.

You could also consider splitting your photo-period if there's a time in the afternoon when you aren't home so don't care about seeing the fish. I don't believe that an afternoon "nap" actually does anything in-itself to help with algae (some claim it does, but I'm highly skeptical), but it doesn't harm plants any and would let you move to a shorter photo-period.

[jmhart]

Originally Posted by Django

My lights were on 10 hours a day and now are 8. Funny thing - I don't want to get stuck at a photoperiod of 6 where I can never look at the aquarium at all

On my 45g from years ago, I had a 6 hour photoperiod. Turned it on about 1:00 in the afternoon (I left for work at 7:00 a.m.) so that I'd have it on when I got home.

This was the result:

[bitFUUL]

I used a single piece of white tissue paper across the top of my glass lid, to reduce the lighting. Not the prettiest, been working great for months now!

[Wy Renegade]

Black window screen (commonly available at hardware stores - and often cut to the desired length) as mentioned above works great for this. Use multiple layers to add even more shade. I always used this method when acclimating new corals to my saltwater tanks.

[Django]

Originally Posted by jmhart

On my 45g from years ago, I had a 6 hour photoperiod. Turned it on about 1:00 in the afternoon (I left for work at 7:00 a.m.) so that I'd have it on when I got home.

This was the result:

Nice tank! Looks like a lot of effort went into it. Beautiful job!