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Re: Playing with nutrients and test kits

Hope to finally be able to post without bothering Cynthia to forward
messages for me. Had to change to another mailbox.

from Tom Barr:
>you should define a set of of good parameters for your test subject,
>I define them as 
>CO2: 20-30ppm
>NO3: 5-10ppm
>K: 20-40ppm  
>PO4: .4ppm(hazy on the lower range)-1.0ppm
>Traces: Hazy, I go to 1.0ppm Fe or so 1 hour after addition. Some go with
>.1ppm. Harder waters will need more.
>GH: 3-25
>KH: 3 and up
>NH4: 0.05 or less
>Good tank mixing, filtration etc
>Lighting 2-4 watts a gallon

Tom, An excellent list of all the important ingredients for general plant
growing purposes.  The only things you may have left off are "plant
density" and "experience." Of course, lots and or fast growing plants are
needed for those level of nutrients. But more importantly, I would HIGHLY
suggest the higher end of range of some parameters for the more experienced
underwater gardener. -- DEFINITELY, lower PO4 levels for the beginner, and
for folks with the softer water. Too risky to cause algae to become
established and for them to not notice that the plants are not responding
positively before it is too late. Other comments:
*Regular and sizeable water changes are recommended - (which you said
later), and
	- size and frequency increase with higher nutrient dosing.
*GH should include good balance of Ca and Mg - ~3:1 for softer water,
higher ratios are OK for harder. 
*Important to prevent the K  from exceeding the suggested range with soft
water or there can be problems with Ca uptake.
*For comparisons to N and P: P is ~1/3 of PO4 and N is ~1/4 of NO3
*less PO4 is needed in water column for "rooted" plants; especially in
established tanks which can have a P reserve in a soil/laterite substrate.

Readers should comment and add other points!

> Folks with low CO2 will get algae (in this case our indicator
>preturbation->poor or low CO2 with high light, PO4, NO3 etc all at the
>preset range except for CO2) and poor plant growth. You need to make sure
>the other nutrients are in good shape during this period. 

What are the other combinations that will result in algae?