If you use some thin aluminum sheet metal, like roof flashing material, and make a reflector which has a cross section like \_/, with the bulb in the middle, so you can see a good reflection of the whole bulb on each side of the actual bulb, you get double the PAR from the bulb compared to having no reflector. Really good, well designed, highly polished reflectors can give about 3 times the PAR of a bare bulb, so the simple reflector made this way is pretty good. I don't think a circular shaped "trough" reflector would work nearly as well.
I found what looks to be a cheap DIY way to light my 20 gallon longs with what I hope to be medium to high light. It involves placing XYZ bulbs in the top of a metal duct shaped into a semicircle. see link below. I can't find any specific info on the reflectivity of that shape or how to determine how far from the apex of the circle to place the bulb for optimum light dispersion. Thinking about it, it seems like a parabolic shape would be better, as well as a reflective triangular shape running the length of the duct the width of the bulb to prevent strikeback. I know there are a more factors than you probably care to address individually, but if you know of an application or website to point me in the right direction, it would be appreciated. Or you could build the reflector yourself, test it with your par meter and give me the specs. juuust kiddingg... kinda. :-) any feedback is appreciated. thank you. http://www.youtube.com/watch?v=Xy5fzPlsXK0
I don't recall ever seeing 40 watt screw-in CFL bulbs. If I had seen them, and they were 6500K bulbs, I would have bought one to play around with. One problem: the dome type reflectors from Home Depot aren't big enough for a bulb much bigger than 26 watt, and even those extend beyond the rim of the reflectors. This makes it harder to use the bigger bulbs, unless they are also the miniature type.
When T5HO bulbs are used in good quality reflectors, their light usually doesn't extend for a great distance to either side. So, 4 individual bulbs, if separated by 6 inches or so, may not give you excessively high light. Otherwise, you definitely need lots of CO2.
hey mr lighting guru, im picking up a nice 75 gal tank stand and canopy, im pretty sure the answer would be yes but im gonna be running 4 54watt t5 ho's under the canopy, th brand is ice cap its seperate bulbs not a fixture was just wondering if ill def need to provide pressurized co2 or what
A PAR of 80 is high light. To use that much light you need to use non-limiting fertilizing, and CO2 adjusted to the optimum bubble rate for your set-up. Otherwise, you are just inviting algae, especially BBA, to begin growing.
Hey hoppy, i have been in the hobby for almost a year now. I looked at your par chart early on and had a hard time understanding it. Now after some time i revisited it. Im Upgrading to a 75 g tank And wanted your opinion on lighting.
i was thinking of going with the aqualife 4 x 54w t5 ho and based on your chart if i hung it at about 8 inches above tank, i would get a par of about 80.
I dont want to be limited on what plants i can grow and would like to get a nice carpet going. would that be considered overkill? I will be running pressurized co2 and dosing ei.
The Marineland light would give you very good low light, so that CO2 would not be needed. The others are designed for reef tanks so they would very likely be too much light for a planted tank, and would make the tank look weird with the actinic LEDs.