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Question about metal halide lights

783 Views 5 Replies 3 Participants Last post by  thelub

I have a 135 gal tank that has insufficient lighting. Just found an incredible deal on either metal halide lights or t5ho lights. I have never used mh lights so how many watt metal halide lights would I need for this tank it's six feet long ~24in tall and 18in front to back. For the metal halide i can get either a 70w, 150w, or 250w setup. The t5ho only come in four foot or three foot lengths but I can get two of the three foot to cover the entire tank. The t5 come in either two bulb or four bulb configuration with the 4 bulb having 4 x 39w and the two bulb having 2x 39. Any of these options is available I just don't know which is best suited for my needs. My other question is that I read that metal halide lights depending on how high they are mounted/hung have a light coverage of roughly 2' square. Should I therefore get 3 of the metal halide or would 2 be sufficient just mounted higher. Thanks in advance
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My 125g tank is lit by 2 250 watt halides. I have complete coverage and no dark spots and it is very bright. So far I have been able to keep any and all high light plants that I have attempted. With the right reflector you should be able to Mount it 10-16" above the water and get perfect coverage
I was told 250's might be too much, do you think 150s would work as well? I want to be able to grow things similar to what I have in my 20H which are ambulia, cryptocoryne wendtii, ludwigia (narrow leaf?) Red bamboo, purple bamboo poeceae sp., Bacopa, and glosso.
I believe the 250's are definitely on the high side. 150's should be fine if they are a little closer to the water's surface.
Just be aware that MH run HOT and can affect the heat of your aquarium. That's why marine tanks have had to run chillers for so many years because of all the MH heat it would heat the tank up too much. That and MH will make your powerbill skyrocket. MH definitely do the trick, but T5's will consume less power. Oh yeah, MH bulbs are spendy to replace every 6 months too.
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