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Old 20-04-2003, 07:21 AM
Dave Millman
 
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Default Timing: NO3 addition/measurement

SLEngst wrote:

Need help with logic, timing of addition of NO3 additives vs. measurement
of NO3 levels after addition. Is addition most beneficial in the AM? I want
to attain 5 ppm (I'm up from zero to 0.2ppm). At what time, relative to nitrate
addition, should I be doing the measurement? Directly after addition? or some
period of time later, say 12 hrs? 24 hrs?


In general, you must wait "a while" to measure anything you've added. If you need
to measure something you have dosed directly, such as measuring nitrate after
dosing nitrate, an hour with sufficient circulation is probably enough. If you need
to measure the RESULT of something you dosed, such as measuring pH after turning on
CO2 or adding baking soda, many hours may be required (and the measurement changes
over the course of the lighting period!)

Another issue:Well mixed liquids diffuse to all areas of the tank quickly. If you
are adding granules of something, you need to figure out or observe how long it
takes the solid form to dissolve. If measurements are at stake, predissolve the
solids to avoid this uncertainty.


The consensus would be to add macronutrients twice a week, but build up slowly
so avoiding fish shock. Starting at under 1/2 dosage one M. praecox hit the
dirt (gravel). Should I use daily additions to build up?


Slow is mandatory. I raised measured nitrate by less than 2ppm per week (near 0 to
about 10 over 6 weeks) without ill effects on anyone. Plants liked it though!

I prefer daily dosing for one simple reason: it's a simple habit to squirt 10 ml of
prepared solution into the tank each morning, particularly when caffeine does not
activate my brain for 2-3 more hours. When I was dosing twice weekly, I tended to
lose track.

(Light's dawning - I
had to tear down, clean and replant the tanks maybe a month ago, perhaps I over
cleaned the flourite? and hence the value of my N additions seem zilch until I
build up some mulm?)


You removed some nutrients. If you removed the majority of your aged mulm, then
your nitrate production level may have gone down. But that does not change the
"value of your N additions." You took out mulm which was contributing X ppm per
day, that's all.