Switching from MH to T5?

[kwirky]

using that 48" fixture on your 60" tank will give you a lot of shadow on the sides but it's dooable. There's a guy on RC that tested T5's with a PAR meter going all the way down his 24" tank. Someone else compared his results to another person's test of 250W MH 10k lighting at 24" and the T5's were about 10-20% brighter. That was with a fixture running 50% 10k's, 25% 14k's and 25% actinics.

With T5 you open up the flourescing ballgame though. Anyone seen those flourescent tanks? they look pretty cool .

As for the electronic vs. tar ballast debate, a 250W electronic ballast will draw only 250W while the TAR will draw like 300W. the TAR ballast will output 300W of light however, while the electronic outputs 250W.

Some people go the whole mile and pair specific bulbs with specific ballasts because you'll get different colour temperatures out of them. Especially for the 400W bulbs.

[midgetwaiter]

Originally Posted by kwirky

As for the electronic vs. tar ballast debate, a 250W electronic ballast will draw only 250W while the TAR will draw like 300W. the TAR ballast will output 300W of light however, while the electronic outputs 250W.

You certainly get more PPFD out of an HQI ballast but that doesn't always hold true for standard magnetic, especially with 10k bulbs.

Originally Posted by kwirky

Some people go the whole mile and pair specific bulbs with specific ballasts because you'll get different colour temperatures out of them. Especially for the 400W bulbs.

PPFD varies considerably as well in some cases.