New double T5 HO and CO2?

Limeylemon

I'm wondering after it was brought up in a different discussion.....
I have a 34g soon to be heavily planted tank, Currently using a t8 15watt but upgrading (as soon as the bulbs arrive) to a double T5 HO 24watt light.
It was brought up that i need strong light with a CO2 system, Will it work with this T5? It will be a tetra CO2 optimat setup.

DKRST

The current consensus on forums that discuss pressurized CO2 and lighting seems to be that medium or medium-high light is better than "high" light. A slightly reduced amount of light gives more "oops" room regarding algae and CO2 levels. From my reading, most folks using pressurized CO2 have, at some time or other, killed their fish by using too much CO2. Using less light allows lower CO2 levels and thus, a larger safety margin while still increasing plant growth and reducing algae issues.

Two T5HO bulbs mounted just at the top of the tank provides light levels that are "too high" light, even with CO2, on an 18" depth tank. I'm not familiar with the dimensions on a 34 gallon.

Limeylemon

The main reason im going high light is to have a lot of floating plants, i did it before and all the plants below it died due to low light. So the light is not going to be too intense i believe.

1077

Removing a portion of floating plant's every so often so that light can reach bottom plant's is what most folks do.If you let floating plant's cover the surface,then yes plant's below will suffer.
You can try the light, but I suspect Algae and lot's of it will be the result unless you raise the light fixture up off the tank 8 inches or more, or cut a piece of aluminum window screen to fit under the light if it is to rest on the glass.(may need to double it)
Co2 plus high light,, will place a demand from plant's for more nutrient's both macronutrient's, and micronutrient's.(more than is found in most supplement's)
In the absence of these on regular basis, plant's in my view won't perform much better than simple low tech,low light tank,with weekly addition of product such as flourish comprehensive which you may already be using.

DKRST

Even increasing the light won't necessarily be sufficient. The transmitted light (light passing through the floating plant's leaves) will not be the proper wavelength for photosynthesis to be optimal in your rooted plants. Most folks, as 1077 suggested, prune back their floaters. I try to keep mine at about 25-40% of the total water surface. I'm finding that 25% works best for my tank.

Limeylemon

I'll be still giving the light a bash (cost a lot) for a while, see how it goes, if not i'll downgrade back to my t8. After a conversation with byron a while back we settled on t5 being a good idea with my tank, so much confusion in the aquarium world!

Mikaila31

T5 is a good idea compared to T8. The issue here is not the bulbs you are using its the amount of light. You are switching to a more efficient bulb type while at the same time increasing wattage. A T5 HO produces a lot more light per watt then a T8. You originally had 15 watts of a T8 bulb. You are switching to a fixture that can produce 48 watts of T5 HO lighting. Your light increase from this switch is easily 5 times what it was before if not more. Its not the fixture itself that is the problem its the amount of light you are putting over the tank. A single T5 HO fixture that could run 24 watts would of been a better choice.

Byron

Agree, and since my name came up I would remind you that I did suggest a single tube T5 as being ample. Dual-tube T5 is a lot of light over any tank (relatively speaking) and in my opinion not advisable without high-tech.

Limeylemon

I struggled very badly with finding a single T5 fixture, the single fixture byron found (yes your name again :)) was only available in the states and i'm in the uk, It does say that my double fixture is fine to only use with a single bulb. Think i should just do that for now?

Byron

If the fixture will light with just one tube in it, fine. Some won't, but some will, it depends how they are wired.