Light Questions

You may need to clarify a few things so others can better assist. I will not get into LED fixtures as I tried five and all went back; if you know what you need and what you are getting, this can be ideal lighting. I am using T8 fluorescent tubes on most of my tanks and CFL bulbs on the two smallest tanks.

Wattage is not an indication of intensity because there are so many very different types of lighting and watts is simply the measurement of energy (electricity) a light uses. Unless you are comparing absolutely identical tubes or bulbs, watts is basically meaningless with respect to intensity.

If you have 4-foot tubes at 55w each, I will assume it is T5 fluorescent. T8 in 4-foot lengths is 32w. These are standard, but again different tubes can produce significantly different light intensity (and spectrum) even if all the same wattage. It depends upon the phosphors.

So back to your T5 (presumably)--this is extremely bright lighting. You mention not having high-light requiring plants, so I would suggest that you want a lot less light over the tank. T5 works very well over marine tanks where high light for corals is needed, and over freshwater planted tanks if high-tech, using diffused CO2 and daily nutrient fertilization. As for the fish, they would be severely stressed under this much light.

The largest tank I had was a 5-foot 115g, length 60 inches, width 18 inches, height 24 inches. I had two 4-foot T8 tubes, and grew lovely plants; Amazon swords thrived, and I had a good cover of floating plants as well. I tried two 4-foot T5 tubes (55w each) and it was way too much light for the fish, and algae would have been a mess if I had not removed them after a week. That may give you some idea of the intensity here. Just for comparison, the photo is of that 5-foot tank with the two T8 tubes; one was 6500K, the second was 5000K which provides thee best spectrum. That is another thing to keep in mind--spectrum. Plants need red and blue to photosynthesize, primarily red, and adding green provides a true colour rendition and does help plants, probably because the result is closest to mid-day sun. LED is often blue-heavy, which can increase algae but not do much for many plants. There are good LED fixtures for planted tanks, and others can comment on those.

Thank you for that information Byron! Very helpful.
Yes at the moment I am running 4 x 55w T5HO lights with Daily CO2 and Fertilizer in tab and liquid form.
I have quite a few floaters but now I'm thinking based on your information that, that may be too much light for the fish in my current 60 Gallon, but no algae at all.

I'll scrap the LED models. The other model I was describing, is a total of 8 36" T5HO bulbs, and total length of 72"

Your tank looks stunning by the way, that's awesome! So I guess back to my first question then, would 4 x 55w T5HO laps at 48" Length be enough for a 72" tank. I can make it 5 Bulbs in needed. Or would I be better off with the 72" Light bar with the 8 Lights.

Java ferns, Jungle Val's, Amazon Swords are pretty much what I'll be growing.

I am hesitant to say much beyond what I previously posted, because you have CO2 diffusion (which I never have done) and that raises the light/nutrient balance level. I had two 4-foot T5 HO tubes over the tank in the photo and it was so bright I took it back, and repaired my old T8 to have two T8 tubes. You are talking about doubling the T5 light I tried, over a tank that is only a foot longer. For me, I would never do that, but again you have CO2, and the duration was not mentioned.

For comparison, one T5 is roughly 1.5 times brighter light than one T8 in the same length and of the exact same manufacture (I was using Life-Glo 6700K tubes when I tried the T5). So considering my tank in the photo, with two T8 tubes...two T5 added the equivalent of another T8 tube, and if I had used four T5's I would have be equivalent to six T8's, or three times what is in the photo. That would have seriously affected the fish, which is always my prime concern.

Seriously your tank looks great! No CO2 just fertilizer? I noticed Tetras, how many do you have in your 115? What is the name of the smaller plants in front? Love to see more pictures if you have more?

I am going to stick with my Lights for now and just see how it looks and how the fish and plants react to it. Tank should be here Friday. I probably should have mentioned I'll be having the light fixture hanging about a foot above the tank, so it should be able to reach the ends of the tank. I run CO2 8 hours a day.

Could I also get your opinion on 1 more thing, sorry for all the questions but you obviously know what you're doing. At a 120 Gallons, is a canister filter required? I wanted to avoid them due to bad leaks in the past. Can I do 3 Aquaclear 110 Hang on Filters instead at different lengths? I do 50% percent water changes and vacuum the gravel weekly so I'm not too worried if they don't perform as good as a canister filter. Your opinion on that?

Thanks for everything.

Hamsnacks said:

I noticed Tetras, how many do you have in your 115? What is the name of the smaller plants in front? Love to see more pictures if you have more?

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That photo was taken in May of 2014 and there were about 80 various tetras, Bleeding Heart, Garnet (Pretty), Rummy Nose, Cardinal, Black Phantom; 40-45 cory catfish, a Bolivian Ram, 2 spotted woodcats, and the group of 8 or 9 Platinum Hatchetfish. Probably a few otos too. The small swords are Helanthium bolivianum (the larger of the two species of pygmy chain swords), with Echinodorus grisebachii (var. bleherae) the main large sword (most seem to have had inflorescences when this photo was taken) and an Echinodorus cordifolius. I think the floating plants then were Water Sprite, Frogbit, and Brazilian Pennywort. I tore this tank down in April 2016 because it was over 20 years old and frankly I was worried about the seal giving out, and I replaced it with two smaller tanks. Attached photos show what it looked like in September 2009 and November 2010.

Hamsnacks said:

I am going to stick with my Lights for now and just see how it looks and how the fish and plants react to it. Tank should be here Friday. I probably should have mentioned I'll be having the light fixture hanging about a foot above the tank, so it should be able to reach the ends of the tank. I run CO2 8 hours a day.

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Yes, hanging the lights should help reduce the intensity, especially with a good cover of floating plants. And should not be too problematic for the ends of the tank; I had a 6-inch no-light gap at the ends of the 5 foot tank, and used vertical chunks of wood representing tree trunks to fill in.

Hamsnacks said:

At a 120 Gallons, is a canister filter required? I wanted to avoid them due to bad leaks in the past. Can I do 3 Aquaclear 110 Hang on Filters instead at different lengths? I do 50% percent water changes and vacuum the gravel weekly so I'm not too worried if they don't perform as good as a canister filter. Your opinion on that?

Click to expand...

I do not like HOB filters; I used them back in the 1980's but no more. Yo do need something to move the water end to end, and create surface disturbance (in relatively heavily planted tanks you can get a shortage of O and increase of CO2 during darkness, so surface disturbance I have found important). I had a Rena Filstar 3 canister on the 115g, For tanks in the 4+ foot length, I personally would not use anything but a canister. My present 90g has an Eheim Pro II with built-in heating unit, and my 70g has an internal Fluval (rated for a 40g) at one end just to create surface disturbance and flow. Forest fish do not appreciate bright lighting but they also do not like strong currents.