Limit NO3 by upping PO4?

Gilles

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Somewhere i've read that Tom said; you'd have to maintain a PO4 of about 2-3, to prevent P deficiency. We all know that the reds in plant becore more lush when you have little NO3; mostly use 5-10 ppm NO3 here in holland, in combination with < 1ppm PO4.

But is it also posible to have for instance 15-20ppm NO3 in combination with 2-3 ppm PO4? Doesn't that doe thesame? Off course, considering light is approx 60mmol and your co2 is arround 30ppm...
 

dutchy

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No, it's not the same The red coloration is created by stress of a slight NO3 deficiency. I'd never risk it, being close to a real deficiency. Since 15 - 20 ppm doesn't create any stress, it won't give the same effect. Also using light at around 60 micromol will give you a little bit less coloration, aromatica's and stellata's will stay more green than under high light. CO2 doesn't play a role in this coloration.

But if you want to play Russian Roulette, and you feel lucky, you can use low nitrates and high light and enjoy the colours....until the algae outbreak happens ;)

regards,
dutchy
 

Tom Barr

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You also get BGA with lower N, it causes more havoc in general to plant health than P limitation.
The issue is that enzymes are specific to a narrow range of concentrations, so they have to make new enzymes when you adjust or vary too much.

This adjustment is fine if it's slow, but rapid extremes cause more issues.
Also, we have alot of issues with determining if their tanks really are 5-10ppm for the entire time they claim.
1. Do they test that often? As in every 1-2 days?
Or just test a few times and assume from then on?
2. Are their also sediment sources of N?
Why doesn't that affect color?
3. What about good CO2 and or other nutrients? Are we sure that in their tanks, it really is non limiting and thus independent of N?
I have grave doubts as to the data given, we also do not know the light values for many of these examples, we ONLY have some N and P data, little more............

Without the other data and confirmation.......we really cannot say that much, neither can they also!!!
But they try and say anyhow..........

Therein is the problem.

I think adding more GH booster, sediment ferts etc, as well........is a better approach and also light colors, photo shop and other color manipulation that has little to do with the real color.


Regards,
Tom Barr
 

Tom Barr

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You might read the Enzymes Articles(#2-3 on the BR articles) also.
Plants use the LATS and HATS to adjust for optimal uptake of NO3.

They also do this for K+ and PO4 etc.
Also likely do as well, particularly green algae.

Regards,
Tom Barr
 

barbarossa4122

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Hi,

I keep around 30ppm of NO3 in my tanks. Now, how much should my PO4 be ? Or best NO3:pO4 ratio?

I dose 30ppm NO3/ week and 6ppm PO4/week.
 
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