[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Potassium Deficiency

Jennifer Glover is wondering whether her tank might have a potassium
deficiency.  I think you might have a potassium deficiency, Jennifer, or
at least a macronutrient deficiency of some kind.  Either potassium or
nitrate, or perhaps both.  What I wish I knew was how much lighting you
have on the tank.  I'm guessing you're in the 2-3 watt per gallon range
since you have CO2 supplementation in the 25 ppm range, right?

Your fish load seems on the lighter side of 'moderate' to me which also
leads me to suspect a macronutrient deficiency.  One of the reasons I'm
a little hesitant on how to advise you is because I've never used
Mira-vit or Ferro-vit.  Because your 2nd and 3rd pictures show a fairly
lush green, I'm guessing the Ferro-vit is providing the iron your plants
need.  The plant leaves looked fairly washed out in the first picture
and left me wondering if there was enough iron in the water column
before that picture was taken.  Do you know what the contents of these
fertilizers are?  BTW, great to see photos illustrating the problem your
working with.  Three cheers for you!

My recommendation would be to try 1/4th tsp. of KNO3 weekly and see if
you notice any improvement.  Should be available at your local garden
store.  I suspect you'll see an improvement, and that you can tweak the
dose one direction of the other based on your conditions.  

You could also insert a few quarter inch pieces of Jobe's plant sticks
in the substrate near the sword roots.  I use tweezers to get the pieces
to the very bottom of the substrate.  However, I have noticed in my
tanks over the last year that if I maintain a little K and N in the
water column, the swords seem to do quite well without additional
fertilizer at the roots.  There won't be any risk in trying both as long
as you don't over do it.

Good luck and let us know how your tank grows!

Regards, Steve Dixon in San Francisco