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.
Aquatic Gardeners Assoc.