View Full Version : Shop lights

12-03-2009, 04:50 PM
In my fish room I have a series of 20L aquariums. Lighting is 4' long 2 tube shop lights. I have two light fixtures over each three tanks suspended about 8" above open tops. Each shop light has two 40 watt 6500k daylight tubes. Would that be considered low light, med. or what. What plants would work well. Fish are my main concern and I'm not really interested in rare plants. But a nice green forest for my apistos would be nice.
I've never had much luck with plants. I can raise fish... not so much with plants. Duckweed is doing well tho... how many HAP points for duckweed???
Ron VanZant

12-03-2009, 05:17 PM
I have a 2 tube T12 shoplight 3" over a open top 20L using a cool white and a grolux bulb and have a medium light level. Even with the additional height you should be able to grow med low light plants and possibly med light plants.
Hygrophilia sunset, H. augustifolia, H. difformis, green rotala, pennywort. If you have a soil or sand substrate swords, crypts, dwarf sag, criniums, should do well. Ambulia should do well also.

12-03-2009, 09:17 PM
I think your lighting is fine. I use shop lights on all my tanks. Mostly T12s, but have T8s on rack of nine 21 gallon tanks. It might just be too much light for the amount of nutrients your adding. Having a lot of light can overdrive your plants into starvation. Do you inject CO2 or add Flourish Excel as a carbon source? Do you fertilize your plants?

You can at least get 5 HAP points for that duckweed.


12-03-2009, 09:28 PM
A few inches can make a huge difference in light intensity.


At 8" vs 3", the difference in intensity at the substrate would be a lot higher than you may think.

At ~15" above the substrate, 2x40W would probably be medium light.

12-04-2009, 08:12 AM
Thanks for the replies everyone. FSM, that link was very helpful. I'm not adding any chemicals but I guess I could if it would help a lot. I just don't want to mess anything up. As I said, the fish are my main concern. I also don't want to do the CO2 thing. I do have some of the Seachem substrate. I think it is Fluorite. I've had it for years and don't remember the name... Sooo, it sounds like I'm looking at med light plants that don't need CO2 or any special chemicals.

Larry Bugg
12-04-2009, 10:11 AM
Just keep an eye on it. I have shop lights on my racks holding 10's, 15's, 20's and 3 55's. The 15's, 20's and 55's are all planted. On the 15's I have only one of the two bulbs running. On some of the 20's I constantly fight algae but most of them are just right for low to med plants. Not a lot of growth but they maintain pretty well. I have them hanging about 6 inches above the tanks and they are all on timers running about 10 hours a day. Fortunately I have enough trimmings from my high light tanks that when the algae gets to be a problem I just yank the plants out and put in new trimmings. I do occasionally dose a little excel and flourish but nothing on a regular schedule.

Chris Noto
12-04-2009, 09:38 PM
Duckweed is doing well tho...
Actually, Ron, if the duckweed is too successful in your tanks, whatever kind of light you've got over the tank won't be able to punch through the floating carpet of "d.w.". . .