Magnesium Supplementation

Subject: Magnesium Supplementation

> Another nutrient to seriously consider is magnesium.  Magnesium 
> also causes older leaves to die back.  Typically, they lose chlo
> become yellow before dying.  Often the edges and end of the leaf
> yellow and start to die while the midrib is still green.  Magnes
> deficiency has not been considered very much, but it could be mo
> prevalent than most aquatic plant people think.  If you come fro
> dolomite limestone region, the water will have both calcium and 
> hardness, but if you come from a soft water region, the municipa
> system may add some lime to the water to give you moderately har
> but that water will have very little magnesium.  Fishfood is not
> supplier of magnesium, either.  MgSO4 is easy to get.  

I've had this problem before.  It looks like the plants are iron 
deficient when I know there's plenty of iron present.  When I add 
magnesium (I've just used Epsom Salts... is ther any problem with 
this?)  everything has greened right up.

BTW, I think I overdosed my tank the last time I did this... some 
plants showed no negative reaction, but I lost almost all my H. 
difformis within the next week or so, and some of the other stem 
plants took a bit of a hit too.  The rosette plants, OTOH, look 
better than ever.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA