Question about Hagen Glo light fixture

[JDRawe]

Hello,
I wanted a low-tech (no CO2) planted aquarium. I read that I need 2wpg to achieve this, so I bought a 2X54w t5ho Hagen Glo light fixture for my 55g aquarium. Now I am reading that the wpg rules do not apply to the t5ho bulbs. What should I do? This unit is on its way to my house via FedEx right now. Is it possible to only run one bulb in the unit? Will it still work this way? Someone please give me some advice on this... I really didn't want to have to set up CO2. If I use this light fixture, will CO2 be necessary?

 

[cjldad]

Hi JD, welcome! I would go ahead and accept that fixture from the Fedex man.. I think you will be on the edge of going Co2.. Also, would suggest breaking up the photo period to help reduce an algae outbreak. i.e. 4 hours on, 4 off, and 4 on.. Then off till the next day.. How are you going to get a carbon source in the tank? Excel? Plan on dosing ferts? Good luck, I'm about to order the plants for my tank..

 

[JDRawe]

I was hoping not to have to use any ferts or CO2. I just wanted to grow some slow-growing plants with 2wpg and have things be really simple. That's why I got the fixture so I'd be right around 110w. Then I found out with t5ho lights, that it would be more like having 2.76 wpg. So you think i'd be okay without CO2 with that much light?

 

[mfdrookie516]

i think if you dose ferts, you'll be fine... if not, you could probably run an actinic bulb and a daylight bulb, knock the wattage down to 54w, and you could do some anubias, java fern, and moss easily, possibly some others. it all depends on what you're willing to do... dosing ferts is easy

 

[jsoong]

There are many other factors in addition to he wpg, such as the depth of the tank, how high you mount the light, the efficiency of the reflectors, and how long the light is on. So, no need to panic. You might be pushing 3 wpg, but you can still do OK without CO2. It is a matter of balancing out your fertilizer & the lighting period & the number of plants you have.

The main problem with too high light is algae growth. You can limit that by having lots of plants (and some fast growing stem plants (at least until the slow ones grow in), and giving the plants optimal growth conditions. <That usually means adding some ferts, but it is easy to do.>

You can also play with the photo period, maybe breaking it up as others had suggested. If you have to decrease the light level, some fixture will allow you to light just one bulb. It all depends on what ballast is in the fixture & how it is wired. <Take out one bulb & see if it will still light.> If all else fails, you can always swap in an actinic bulb to decrease the light that way.