xathine

Just found a killer deal for a 36" T5 HO fixture for my 30G Long tank.

It will put my WPG at 2.6 I don't want to deal with CO2. Just a simple low/med light planted tank is what I want.

I fear this will be over-kill for my tiny setup and everything would die with the lack of CO2 injection...

Any input? Kid only wants $40 for it and will be a big improvement over my 20" florescent fixture I have now keeping me at .6 WPG lol

mathas

2.6WPG of T5HO, especially if the reflectors are decent, is a lot of light to not use CO2. Even moreso when the tank is a "long" (i.e. shallower).

If you don't use a ridiculously small photoperiod, you may wind up with a massive algal outbreak.

xathine

Lame.

So would it be okay to use in smaller on / off increments?

Like on for only 6-8 hours a day?

harpua2002

I agree with mathas. To put it in perspective, I used to work for a LFS that used 108W HO T5 over each planted 55 gallon tank. The 108W HO T5 were MUCH brighter than my 130W PC light that I had over my 55 at home. With decent reflectors, they really put out a ton of light. With 2 daylight spectrum bulbs over a 30 gallon, there's no way I'd try it without CO2 and ferts; IMO it would be an algae factory. However, it might work if you swap one daylight bulb for an actinic (plants can't really utilize the actinic spectrum so it would be like using lower light).

xathine

Hmm, what would the color of the light look like with the antinic?


Also, wonder how well it would fit / work for my 55g.

harpua2002

Probably better than you'd expect. I kept a medium light planted tank in a 45 gallon tall (36x12x24) with only a 2 foot HO T5, 2x 24W. They put out a lot of light.

Running it with one actinic and one daylight will make the tank look a little blue. You can probably mitigate that a little bit by choosing a 6700K instead of a 10000K for your daylight bulb. Just a thought.