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

Supplementing PO4

Steve Dixon wrote:

>I'll let you all in on a little bit of heresy I've been experimenting with
>recently.  Many of us strive to maintain phosphate-limited conditions in our
>planted aquaria.  This is one of our basic algae control strategies.  But
>what do we really mean by that phrase?  Can there be such a thing as having
>too little phosphate?  And what does fish feeding have to do with this
>issue?  Will a heavy feeding schedule provide sufficient phosphate for
>"optimum" (uh-oh, I'm in trouble now :-)) growth.  My preliminary
>observations are that one can have insufficient phosphate levels and that
>this condition can occur in tanks where the fish are fed heavily!!!  I'm
>using 1/10 gram amounts of potassium monobasic phosphate with quite
>surprising results (beautiful, is actually the right word for it) under a
>variety of high growth conditions.  I have a fairly good feel for what this
>supplement is doing to nitrate levels (driving them down, as one would
>expect).  I'm just starting to focus on the effect on potassium levels.  

Funny thing.  Karl Schoeler and I were recently discussing this very thing.
 Both of us had observed that our Rotala macrandra seemed to take a hit if
PO4 levels dropped too low.  In the last year or so, my town has started to
add phosphate ot the water to protect the pipes.  I had been dreading that
day for several years, as I'd heard of other people having problems
maintaining planted tanks without algae problems with phoasphate in the tap

I have found that with .5 ppm phosphate in the tap water that not only do I
not have algae problems, but in high light, fast growth tanks, the plants
perk right up with a water change... a phenomenon I attribute to the influx
of PO4.    Even when I set up a new tank, I haven't had algae problems, and
that initial .5 reading quickly drops to undetectable in the tanks.  

So I guess, heresy or not, I agree with you ;-)