[APD] Re: NH4

[Thomas Barr <tcbiii at earthlink_net>]

>> Well "a sort of essentail" cation that helps induce spores 
>>into vegetative mode. Niether is truely essential, since 
>> both can live on NO3 but the spores don't seem to grow 
>> without the free meal of NH4.

>But isn't algae working in the ppb-range? The plants are 
>NH4 limited *long* before algae so their removal capacity
>of NH4 doesn't matter much to algae?

No, not really. You still need a certain amount of NH4 to work with.
The NH4 is in the ppb range, but is being consumed by plants very fast.
If something disturbs the plants, then a slight increase in NH4 will trigger algae.

This triggering by NH4 is fairly tough to induce though. While the NH4 ppb ranges might seem small etc, the plants have to have something fairly major occur to stop the NH4 uptake.

And this also makes sense in terms of NH4= algae.

Major things like low CO2, no NO3 etc can really set the plant back, things like Fe deficency etc will not. 
So 95% of all algae problems are related to CO2 & NO3. A few to PO4/K/Traces/GH.

These cause major probelms for the plants trying to take in NH4. 

>I thought the trick was steady stable nitrification (filters+substrate)
>rendering the NH4 to NO3 instantly/fast making the 
>NH4 levels stable and (too) low both for algae and plants.

No, you can use both the bacteria and the plants to do this. 
Plants seem to dominate over bacteria. 
NH4 is not bad for plants and perhaps some is good. 
NH4 is not needed for good plant growth though.

Some seem to think it is.
Ain't true one bit.

The loading is not steady nor established yet in a new tank. Adding mulm etc helps establish the bacteria and fungi but it still takes a few weeks to really settle in. 

>This would make NO3 the only nitrogen source which
>plants with their big biomass can handle but the algae
>sit and wait for next NH4-spike?
>(comparing to what you usually say about phosphate)
> Daniel

Well that's typically what happens anyway.
It's when plants stop taking in the NH4 that causes an issue.

The NH4 levels are very low and tough to measure so I cannot give a precise ppb yet that induces the GW.
But it's not much at all and it's removed fast.

Other things like high light + CO2 really play a role.
So there is interaction with other parameters.

Low light tanks are rather tough to get GW and other algae.
High light tanks are much more sensitive.

That's one reason I suggest

  




 




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