Re: Scott Corbeil's H*E*L*P request

> From: "CORBEIL, SCOTT" <corbels at macmail_mcgawpark.baxter.com>
> I have =
> been using PMDD for approx.  2 months now (minus KNO3).  

	Leaving out the nitrate is asking for trouble.  As far as I can
see, fish food generally has a P/N ratio that is high enough that the 
nitrogen is consumed by the plants, with excess phosphorous remaining.
This assumes that you have enough light, trace elements and potassium.

> I still have a =
> major problem with blue green algae, generally covering the entire tank =
> in a week.

	I'm not surprised.  I scarcely need to test for nitrate any
more - all I do is add more KNO3 if there is a significant amount of
cyanobacteria around.

> Ph.=3D 6.4 - 6.6, Phosphates are non existant according to =
> the lamonte test kit.

	Maybe, but what is the limit of detection?  The concentration needed
to cause trouble is _very_ low.   The cyanobacteria themselves won't
let it get very high - as you have seen, they grow like crazy and
consume it.

> Unfortunately, the lamonte nitrate test kit didn't =
> come in yet so I don't know where my nitates lay. 

	Get _any_ kit available and get a measurment asap.  The answer will
almost certainly be "below detection limit".

> As I state above I don't know where my nitrates are but, based =
> on the fish load, would be surprised if the tank is nitrogen limited.

	If you have a heavy fish load, you _must_ have vigorously growing
plants to consume the P you are adding, and they can't do that if you
don't have enough N.  In my experience, planted tanks run out of nitrogen
if it isn't added and everything else is available.

Paul Sears        Ottawa, Canada

Finger ap626 at freenet_carleton.ca for PGP public key.