Re: Aquatic Plants Digest V1 #242

>From: mleather at tbdmil_com

> > Well today i started of my CO2 injection system after noting that 
> > all
> > the leaves on my Amazon swords were developing brown spots on them.
> > It is only a simple yeast reactor now in my 29 gallon tank but it
> > should be better than nothing.
> > I also checked my initial water conditions before starting the 
> > reactor.
> >         Hardness was at 55 ppm  this seems extremly soft
> >         PH was at 7.6 or higher since that is the max on the scale i 
> >                       used
> >         For lighting i'm using 2 20 Watt GE Full Spectrum bulbs 14 
> >                       hours
>Well after 24 hours of CO2 from a bottle of yeast ph has dropped to a more
>reasonable 6.8 just before the lights went on for for the day.  However my
>yellow and brown spots are still growing bigger. 
>Should I increase the hardness to say 80 or 100 ppm?  Note 55 ppm relates
>to about 3.3 grams per gallon or a bit less.  And if so how much baking
>soda should I use for this?


>From: Nick Livingston <nickliv at halcyon_com>

>I have a few questions.  First off, my 29 gal tank has been having some 
>problems recently.  I've noticed small but increasing amounts of green 
>spot algae and a hairlike algae.  Also, my water wisteria has been losing 
>little bits of leaves, and holes are appearing in some of my other 
>plants.  I add the tetra iron stuff every water change because that's all 
>my budget will allow.  The affected plants are some of my oldest, so I 
>don't think its just that they're running out of stored nutrients.  
>However I could be wrong.  I already checked the FAQ on this and it 
>wasn't any help.  Lighting is two 20 watt FL, and pH is about 6.5.  The 
>fish load is fairly light.  Oh, and the water turns yellow too, although 
>this may be from the driftwood.  Any suggestions on how to get rid of any 
>or all of these problems?

Pretty hard to say, but in both cases it sounds as if the mobile
elements are being transferred out of the old leaves and into new
growth. The mobile or mainly mobile elements are zinc, magnesium,
molybdenum, nitrogen, phosphorus, and  potassium. Deficiencies in
these elements cause older leaves to die or suffer adverse effects
first as the missing element is transferred to the newer leaves.
Someone earlier mentionned that a potassium deficiency will cause
spots on older leaves. Magnesium can be obtained from Epsom salts,
potassium from potassium sulfate. Actually a good soluble hydroponic
fertilizer from a garden suply shop will contain all of the above
elements, although the phosphate levels might get a little high.