Re: leggy plants

[Thomas Barr <tcbiii at earthlink_net>]

> I notice that all the plants in my tank are quite leggy, with very long
> internodes. The tank is 72 gallons, and has 4-55W AH supply PCF lights on 13
> hours/day. What I am wondering is if somehow I am putting in more nutrients
> and CO2 than the lighting requires, and that is why the plants are so leggy?
> Or is it just too little light?

No, it's not the light.

> pH is 6.6, KH=GH=5.5, 74 degrees. 1/2 gravel, 1/2 flourite substrate. Twice
> weekly (at water change and 1/2 way in between) the plants get 15 ml each of
> Flourish and Flourish iron, 1/2t KNO3, 1t K2SO4, 1/16t KH2PO4. The KH and GH
> are normally around 2; the values above come from baking soda and Seachem
> Equilibrium.

15mls of iron is a heck of a lot. Maybe 4-5mls of this would be better. Or
nothing but the flourish with an occasional iron spike. 20mls x a week.
The extra iron etc not going to cause harm but is wasteful. The plants don't
need that much iron.

How big is the water change?
How much of the tank is planted or shaded over? Open well trimmed tanks
seldom have leggy growth. Make sure there's enough light getting to the
plants. 
Reduce the light down to 10-11 hr range.
Nothing major appears wrong. All the macro's and micro's are there and
there's good CO2 and plenty of light.


Regards, 
Tom Barr