[APD] Re: NH4 vs NO3

[Thomas Barr <tcbiii at earthlink_net>]

Date: Wed, 20 Jul 2005 00:19:04 -0400
From: Derek Parr <derekparr at earthlink_net>
Subject: [APD] filters, nitrates, and myths?
To: aquatic plants digest <aquatic-plants at actwin_com>

>the present consensus on nitrates being better than ammonia to keep 
>algae away, 

True but a little NH4 is fine and good in a healthy tank=> eg from the fish.

It's when the CO2 drops or the tank is NO3/PO4/trace limited etc, that we run into problems...........
Then the filter is a much better back up than the plants which are limited.
If no filter/responsive bacterial culture is present, then you favor the algae.

The point here is that it is not cut and dry, one or the other, it's still balance and folks are fine with 100% NO3 if they chose, but a little NH4 in a healthy growing tank ain't bad or worse than NO3, perhaps even better than just NO3.

While folks desire simplicity, life ain't that way, plant life or otherwise.
It's dynamic and the systems push and pull one another.

>and such, has gotten me thinking on the use of standard 
>filter units (minus the charcoal) with planted tanks.

For the start up phase, you may use activated carbon, it'll be spent after 1 month and make decent biomedia.

>  In several places 
>it has been said that it is perhaps better to forgoe using standard 
>filter floss type filtering and to use something simple that just 
>collects the big peices and moves the water around, like powerheads or 
>such.  

No, I like a good mechanical filter.
I use sponge material generally.
Removal of rotting plant material is not bad.

Filters are more responsive that the filterless tanks because the water is well circulated through the biomedia.
So when things go sour, the filtered tanks will be more robust in terms of algae resistence.
Filters make a good back up.
Especially when you have higher fish loads........

If you don';t have higher fish loads, then filterless tanks work well...........gee why might that be?

No fish=> no NH4.
Doh!

You can test this but adding more and mnore fish/shrimp fish food etc to a tank till it breaks and algae starts to grow.

I've done this several times critically. 

>But, based on the idea that nitrates are far preferable to 
>ammonia, then would it not be better to have a fair amount of filter 
>media?

Yes.

>  opposed to just moving the water around and depending on the 
>plants to take care of the ammonia?  or something in between?
>-derek parr

Well moving the water around the same way, maintaining the same CO2 level when removing a filter etc all come into play..........

Folks LIKE to suggest it's all due to the NH4 vs NO3, but you can go back and dose and test this to see.

And I sure as heck don't see it.
But if I reduce flow and increase CO2(90+% of all algae issues-> CO2 related, not enough CO2), plants do better also..........

So..........it seems there are other things occuring here that have nothing to do with the NH4/NO3.

Regards, 
Tom Barr


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