Just got my new Coralife 4x65 today for my 55 gal tank...Would my tank be considered high light now? I did have 4 32w T8s...A couple more questions...Should one add iron to a tank that is showing no defciences? How important is calcium to plants? My water has a gh of 0, I have been adding epsom salts but havent added any calcium. What are some calcium deficences? If I add 1/2 tsp of Kno3 3 times a week should I dose any K2So4? Sorry for all the questions in one post....

You now have very high light.
Yes, uptake of CO2, then NO3 on down the line will increase if you turn them on the same amount as the 4x32w/gal.

I would have stuck with the T8's personally.
More is not better.

I'd only use all the lights for 4 hours at most and make sure the CO2 is good.


Regards,
Tom Barr

What about the iron and calcium? The t8s I had seemed almost as bright as the 4x65...

Light drives plant growth. So, high light makes the plants grow faster, using more of every single nutrient required for growth. Unfortunately, high light is just as effective in making algae grow faster.