NO3 (or other) uptake rates vs light levels??

Re: NO3 (or other) uptake rates vs light levels??

Laith,
If I'm not mistaken that's for high light tanks (5wpg and up). EI can still be
used for lower light tanks, just lower the frequency of dosing: you would
dose once instead of 3 times per week, and increasing frequency, if needed.

Bill

 

Re: NO3 (or other) uptake rates vs light levels??

Sorry, Laith, I think I've confused CO2 and nonCO2 tank ferting With
50% weekly WC, does it matter? Since you're resetting the values weekly(?)
I'm wondering if it simply means your tank's plants won't grow as fast, but
still be healthy growth compared to high-light tanks.

I would like clarification on high/lo tank lighting. I've always gone with:
1-2wpg=low
3-4wpg=medium
5&up=high
Those with 5&up/wpg seem to push the envelope on CO2 enrichment.

Bill

 

Re: NO3 (or other) uptake rates vs light levels??

And we haven't even addressed the bio-load in the tank as to fish, shrimp,
snails, etc, what amount of nitrates are being added by feeding and excreting

 

Re: NO3 (or other) uptake rates vs light levels??

Good question, I tend to underdose fearing I might have an accumulation by the end of the week. I have heard that cherry shrimp cannot survive nitrate levels above 20 ppm.

 

Re: NO3 (or other) uptake rates vs light levels??

In EI article Tom's example is "a typical routine for a high light tank with low fish load", 5.5 wpg, 20 g tank.

I think there is no single scheme that one can make and then get "correct" doses from inputing "tank dimensions" or "amount of light" into it just because there are too many factors that one has to consider. Even in the example above - what is plant biomass, what is exactly "low fish load", what kind of plants was used, and so on.

The only thing which can be considered constant are target and desired levels of NPK, CO2 and traces listed in the article:

CO2 range 20-30ppm
NO3 range 5-20ppm
K+ range 10-30ppm
PO4 range 0.4-1.5 ppm
Fe 0.5ppm or higher (?)

I personally believe that at initial stage you have to do some testing of nitrate and phosphate levels to estimate uptake rates of your particular tank, get idea of your tap water parameters. And then just decide what will be your desired range of nutrients and start dosing at amount and frequency required to get to this range. If you will have to scale things relatively to the EI article recommendations apply the same factor to all elements and do not bother with testing of potassium or iron levels. I personally use nitrate level as a "guide" and scale things in parallel.

And note that recommended ranges are quite wide as plants are very flexible and have great adaptability.

Regards.

Vladimir.

 

Re: NO3 (or other) uptake rates vs light levels??

Okay, I'll be a guniea pig. I've been growing wet weeds for only 4 months now and while I've learned alot, I cannot make these observations with any degree of accuracy. For me, they're either growing profusely, not growing, or dying.

I slackend off for a while on my dosing and after a couple of weeks I noticed that I'd removed all of the Ludwigea Repens. All of it had been slowly dying and the Bacopa and Rotalla were also becoming stunted. The Hygro P. was growing with abandon.

So I'm on a more regimented dosing schedule now and still battling the thread algae that also cropped up during this time. It's hard to say if I'm in the ball park or not. The hygro is still growing rapidly, the Bacopa and Rotalla are still stunted. What else am I looking for? It's hard to judge if the Rotalla is responding, I have to cut the tops off because they're full of thread algae.

steve