Hello All

I am still having problems with a 55 gal setup and need some advice.

This is a 3 month old setup that was originally plastic plants.
About 4 weeks ago I took it down and changed out the substrate to pure
flourite. I also added 110 watts of light ( 10,000 K) and a "bunch"
of plants. I saved the water and kept the filter going in the temp
containers as to preserve the cycle. Everything went well. Since
then:

PH has been stable at @7.0
AM has been non existent
NO2 has been Non existent
GH has fluxed 70-90
KH around 35
NO3 has been off the scale.


I have been doing way too many water change outs trying to get and
keep the Nitrates low and have not been sucessfull. Algae is almost
completely out of controll. Water change outs seem to halt it's
growth for a couple days then it takes off again. I have done 4 50%
water change outs in the last 10 days and again today my Nitrate is in
excess of 80 PPM. When it gets that bad I can not tell the difference
between the shades of red on the indicator card.

Fish loading is heavy but not excessive I think. Plant loading in my
interpretation is Moderate to Heavy. I have cleaned the tank
repeatedly and there is no wasting organic matter. I also do not
believe I am overfeeding. I have little ( 30 watt) 3000k Compact
flourescents on for about 17 hours a day and the big lights ( 110
watts) for about 11 hours each day.

I have read a bit about CO2 and think that may be part of the
problem, but I hate to waste a bunch of money if it is not required.
If CO2 is the only way the wife says get it today!! She is tired of
me doing water changes every other day in her livingroom!
So my questions a

Is it possible to get this under control with out CO2 injection??

Is ther anything else I should be doing/ thinking about??

Thanks

Steve