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Light to cut the green

1610 Views 12 Replies 7 Participants Last post by  gvfarns
I have 2 6500k GE T5HO bulbs over my 20 gallon high. Between the light reflecting off the plants, the algae growing on the back of the aquarium and in some places on the gravel (that I don't really want to scrape off because I want it to feed my ottos), my green and white gravel, and possibly some green in the water (but not much I think), my aquarium seems to have a definite green glow about it. No surprise there.

My question is whether there are lights that I could use in my fixture (maybe one, and retain a 6500k) that will sort of cut the appearance of green, while still promoting plant growth. If I used one of those pinkish plant bulbs, would that do it? Or maybe switch to a 10000k bulb or something? I have a several red fish so something that would also enhance red would be nice.

Additional info: I have anacharis, anubias, java fern, and red ludwigia in here. My tank is fairly new (6 weeks or so) so the plants are sort of just getting established. Although one strategy would be to try and attack algae or reduce the actual amount of green stuff in there, I'm more interested in just changing the appearance by altering the color of the light.

edit: Actually I don't have a background on the aquarium right now either. Maybe there is a particular color I could put there that would help?

edit2: My hood is super cheap. Just one not very efficient reflector. In case it matters.
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Thats alot of light for a 20h. Are you using co2? With that amount of light you likely need co2. You could cut back to 1 bulb for awhile and see if that helps. FWIW, new tanks are prone to algae, so its hard to pinpiont your problem but im guessing its co2.
I'd cut back to one bulb and try a pink bulb.
I have DIY CO2 going on right now, though the diffusion technique (bubble stone) is not super efficient. At night I run a regular air stone.

So you think a plant bulb (pinkish) would work better than 10000K for enhancing non-green colors?
One person here reported on PAR testing of the pink plant bulbs. He/she (I forget which) said the pink bulb produced about half the light of the regular bulbs. That would be a big advantage for you, since you have far too much light now. But, all bulbs work for growing plants.
So you guys feel that 24 watts of T5 is the right amount for a heavily planted (at least, i want it to be heavily planted) CO2 enriched 20H tank? It seems low compared with my previous googling.
Those GE Starcoat bulbs have high PAR so, you could replace one with a pink bulb to reduce your total PAR and see if that helps with the algae and looks good to you. Or, you could take both bulbs out and replace with one 10,000 K bulb to help with the green appearance. You might still be happy with plant growth with the one 10,000 K bulb.

I use 2 10,000 k bulbs (lower PAR than the GEs) on my tank because I wasn't happy with the green appearance of the GE bulbs either. They sure grew plants well though.
Hey, thanks for the replies. Does anyone have a good link for what PAR is and how I should think about it?

But anyway back to topic, I was originally looking for color suggestions and I've sort of heard both pink and 10000k. Assuming the amount of algae and intensity of light is acceptable, which color would likely be best for aesthetically decreasing the green? Or would even more departure from daylight color be better in terms of aesthetics?
10,000 k would be better to get away from the green look. If you were to use a pink, you would probably need to combine it with a 6500 K for sufficient PAR. Pink bulbs display red fish and plants well. The third option is using a 10,000 K with a pink bulb to display reds and blues well without the green.

Below is a link that describes the PAR of some bulbs including the GEs and Geisman bulbs.
Pink is pretty much opposite to green on the color wheel, so it would be the most effective to neutralize a green hue.

If you overdo it, it might turn everything brownish. Then adding 10000K will help to brighten things up.

I find that red plants look best under pinkish light (no surprise), dark green plants best under 10000K and alright under pink lights, bright green plants look best under yellow/green bulbs like the Starcoats.
Defiantly put a black or dark blue background will certainly help make your tank look will make everything pop in a good way.
Thanks a lot. You are all very helpful (further comments appreciated of course, but I did want to thank the people who have taken the time so far).
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