re: CO2

---------- Forwarded message ----------
From: psears at emr1_NRCan.gc.ca (Paul Sears)
Subject: Re: CO2
To: Aquatic-Plants at ActWin_com
Date: Mon, 27 Jan 1997 11:23:51 -0500 (EST)

> From: STDIXON <stdixon at bechtel_com>
> Subject: CO2 Questions
> I think it is.  I'm going to try Tropica Mastergrow (per Randall) as well
> as PMDD when the micronutrient mix arrives--so the question should go away.

	I would not suggest using both at the same time.  The method 
Kevin and I developed was not (as Karen Randall suggested) based on
Tropica Mastergrow; we used logic and experiment.  The plants _need_
K, N, P and a well-known list of trace elements.  They must be provided
somehow, but there is no point in duplicating sources, and I infer 
from what Karen said that Tropica Mastergrow is a trace element mix.

> My plants seem to be doing fairly well.  (I'm so new to a reasonably well
> fertilized aquarium that I'm not certain.)  I'm getting an inch or more
> growth per week from hygo difformis and at least that much for other stem
> plants including rotala indica and macandra.  Amania gracilis is growing 2
> or 3 inches per week.  Java ferns, swords, bolbitis and crypts are growing
> some new leaves each week,

	This sounds reasonably good to me.

> but I also continue to grow algae (mostly green
> spot,

	This is the one algae type that persists in Kevin's main tank
and in my main tank.  It is not obtrusive, but it does remain on older

> but a bit of cyanobacteria persists as well).  

	That is consistent (in my experience) with zero nitrate. 

> Crypt leaves are showing some chlorosis though
> (yellowish and spotting).

	That sounds like a deficiency of something.

> I continually get zero readings for nitrate and iron--seemingly
> no matter how much I'm fertilizing.

	It is worth testing kits with solutions known to contain the
material of interest, just to be sure they work O.K..

>   Phosphate readings are about .1 ppm
> which is my guess as to why I'm growing a fair amount of algae.
	How much is in your water supply?  What is in the substrate, and
are you disturbing it?

> Since I can never get a nitrate reading (and I
> still have phosphate), I have increased the KNO3 (slowly) to a full
> teaspoon per day (still zero nitrate readings).  I observed the (roughly)
> 2:1 ratio of K and Mg to KNO3 in the PMDD recipe--so I have been increasing
> the K and Mg as I have tried to establish low levels of nitrates in the
> tank.  Is this crazy?  Should I be increasing KNO3 alone?
	I would, provided the nitrate test is O.K., and I think it probably
is, keep increasing things until readings do appear.  The K2SO4 and KNO3
should be increased together, generally.

> My source for KNO3 is Cooke's "Stump Remover and Potassium Nitrate." 
> Someone seemingly knowledgeable in the garden shop assured me it's all
> KNO3.  The lable says "13-0-44" and guarantees 13% "Nitrate Nitrogen" and
> 44% "soluable potast (K2O)."  

	That is consistent with it being about 95% KNO3.

> No other ingredients are listed.  Is this the
> right stuff?  Would you put as much as a tablespoon of the stuff in a 125 g
> daily if that's what it took to get a 2-5 ppm nitrate reading?  

	A tablespoon sounds a heck of a lot, but you are quite a bit below 
that now.

> couldn't get an Fe reading (using Sera Fe test).

	Check that test kit too.
> I got the
> impression from the Aqualine Buschke material that reactor efficiency might
> be, in part, a function of dKH.  The material emphasized that one would
> only get the stated performance at 10 dKH or greater.

	I don't think so.  I'm not sure what they mean by "stated performance",
but I can't see what the KH has to do with it, unless you are talking
about the pH you will get, or are controlling for.

Paul Sears        Ottawa, Canada

Finger ap626 at freenet_carleton.ca for PGP public key.