Another lighting question

[teeman]

Hi everyone,
I have read alot about the whole lighting issue and just can't seem to come to a conclusion.People still go by the wpg formula but its my understanding that with the HO bulbs you can't use the same formula is this wrong thinking?I currently have a 80 gallon tank which is 24 inches deep.I have 2 T5 Ho 54 watt 10,000 daylight bulbs in my fixture aswell as a high reflector.My plants just seem to survive not really thriving.I've started injecting Co2 the past couple weeks aswell.I supplement with Flourish and also have Flourite as a substrate. So according to the wpg I would be way under would I not??Any suggestions or information is greatly appreciated!

[dbosman]

Watts per gallon is an old outdated 'rule of thumb'. It was an estimate that worked reasonably well. Then.

This might help you.

[smaug]

You do not have enough light to bother with the use of co2. Your tank would require 200 plus watts of good spectrum to have med light. You could achieve good results with your current lighting if you used anubias and java ferns as well as crypts and vals.I have seen that scale that bos posts.I have seen that prove not accurate in many cases and just as much an unreliable rule of thumb as wpg.

[dbosman]

Two T5HO bulbs over a standard 48" x 18" foot print 80g is moderate to high light. Distance from lamp to the substrate is the determining factor. Keeping in mind that one manufacturers 10,000k bulb is another manufacturers 6700k, you should be able to grow anything you want.

Other factors are your substrate (flourite is good at cation exchange, but has little in the way of nutrients), fertilizer regime, and as you are now injecting CO2, how effectively is it distributed to your tank. I'm ran out of gas a couple of months ago and plant growth is retarded severely. Stem plants are growing at .0x inches per day instead of .x inches per day.

I suggest you consider root fertilizers to target specific plants, to start.

If you want to talk seriously about plants, check out the www.Plantedtank.net.

[teeman]

Thank for your reply.Now over at the planted tank forum searching around.Boat loads of info and opinions!

[MCHRKiller]

The thing is, you have high lighting directly under the bulbs...the intensity goes down the futher away from being under the bulbs. For example if your fixture is sitting on top of the tank dead in the middle...you will have low light in the front and back and it will taper to medium lighting the closer you get to being under the fixture. Directly under the fixture will be high lighting.