Lighting for low light plants and fish

[LovesLoaches]

I'm setting up a 190 gallon aquarium (60x27x27) for my clown loaches and need to get lighting for the tank that will not be too much for the fish which prefer low light but at the same time will be enough for my plants. I am planning on having Jungle Val and Java Moss which i know are both low light plants. Is standard normal output lighting enough or do i need to go with T5 lighting or something else? I appreciate your suggestions, thank you.

[DainBramage1991]

The difference in efficiency between T8 and T5 bulbs is miniscule. T8s are inexpensive, readily available, and energy efficient. Until the price on T5s comes down out of the stratosphere, you're better off using T8s. Even with the cost factored out over time, T8s are less expensive.

My tank is 24" deep, and I find that a single 4 foot T8 bulb (natural light type, color temp between 5000K - 7000K) lights the tank up nicely without being so bright that my loaches won't come out during the day. In fact, my clowns are active all day and sleep at night.

My suggestion would be to try a single bulb 4-foot T8 fixture. This will likely provide ample lighting for your tank. If this is not enough, a dual-lamp fixture should be plenty. You can obtain single and dual 4-foot fixtures for very little money at most home centers and hardware stores. There will only be 6" of overhang on each end, so it's unlikely that you'll have shadows, especially if you suspend the fixture above the tank.

[Bennett.Bri]

I read in a few places to be very careful of what bulbs you buy though - Am I correct in remembering to get "full spectrum" and to stay away from plant, daylight or 'soft white' models?

[DainBramage1991]

Full spectrum and daylight bulbs are roughly equivalent (depending on the manufacturer), from what I've seen. I've heard of many people using plant lights with their aquariums, which is certainly beneficial to any live plants in the tank. I don't know what effect it would have on the fish, probably none at all. Most fishes color vision leans toward the blue end of the spectrum, so having lights in the cooler range probably makes it easier for the fish to see their surroundings - At least that's my theory.

I use daylight bulbs in all of my tanks, and the fish seem quite content. In the past, I've used plant lights, soft white, cool white, and everything in between. None of them seemed to have any effect on the fish. I choose to use daylight bulbs because they put out a pleasing color and they help support a decent amount of algae growth. I look for bulbs in the 5000k to 7000k color range, with 6500K being ideal in my opinion.

Here is a handy web page that tells a bit about the difference between full-spectrum and daylight bulbs:

http://www.ehow.com/about_6504236_diffe ... ctrum.html

[Bennett.Bri]

Bookmarked -thanks for the link and the info.

[NancyD]

I think a 5 ft tank that deep will "need" 2 T5 or T8 bulbs to grow most low-med light plants. I don't have a light yet for my 60 x 25, 120g, but I'm planning. I've used 2 T5HO bulbs, 108w, 3 x T8s 96w, & 108w PC (power compacts, now obsolete) over 4 ft tanks x 21 inch depth. 5 ft is more challenging, most "30 inch" lights really are 24 inch bulbs in 30 inch fixtures so there's a gap at the ends that can impact plants. Another thing to consider is if the lights will sit on the glass lid or be suspended over it.

Luckily for me my club has a PAR meter to measure light at various points & depths in tanks, that is really what you need to know, much more accurate than watts/gallon & adaptable to the newer LED lighting (still pricey but getting better). The color spectrum is more subjective based on how lights look to us, not plants or fish. I like the yellowish look of 5000-7000 & so do my plants but the higher color rating is ok too, a bluer, whiter look... depends on the fish too but I haven't been unhappy with the way my fish look.

[Diana]

I am using a fixture that holds 2 bulbs, T-8 over my 45 gallon tanks. These are 4' long, and vary from about 16" to 21" tall.
On my 72 gallon bowfront, 4' long, 24" deep I am using 2 of these fixtures, 4 bulbs. It is also near a window, and one end gets some direct sun, but not much (tree outside) and not for very long.
Just based on what plants grow and which do not, this set up is toward the high end of low light. A few plants do OK in the sunny end, but most plants are not so good in the darker end.
Plants that are at the surface (nearest the lights) are thriving. This has created more shaded conditions under the surface, and the fish are out and about quite a lot.