Lighting and CO2

[blang]

I called Dr. fosters last week inquiring about a light fixture. I am getting a 90 gallon tank and wanted no more than 2 wpg, because I didn't want to have to add CO2. Their tech support said that the amount of light you use has nothing to do with the need to use CO2. I think she told me it was the PH level that determines if you should use CO2 or not which has nothing to do with the amount of light you have.

So, she said that the CF light fixture of 260 watts would be fine to use.

What do you think?

 

[greenmaji]

They said that knowing you were going to have plants? Did they also advise using chemicals to control the algae that exess light with no CO2 will cause? If you use partial antinic lighting like some 50/50 bulbs will drop you wpg down to what you need..

 

[blang]

Yes, they knew I was going to use plants. No mention of algae. they did not recommend using antinic lighting but I can't remember why. I guess I can call them again and talk to technical support and ask them why and ask them about algae and CO2.

 

[malkore]

The person you spoke to was a phone operater, not a planted tank expert.

I wouldn't waste time calling them. Anything you need answered, we can do it here.

They probably told you actinic light causes algae in the planted tank. Not true. Actinic light doesn't contain the full spectrum plants need (red and blue mainly) but the blue light it does have will stimulate bushier growth in the plants.

So as greenmagi suggests, swapping a bulb for a 50/50 or even a full actinic03 would effectively cut your wattage in half, out of the range where CO2 would be required.