Re: Enough NO3?

["Dave Johnson" <dsj000 at attbi_com>]

Tom (or anyone else!), do you have any experience with the canister type trickle filters?  My feeling has always been that they are of inadequate size for the intended purpose, but they have the advantage of eliminating overflows and other plumbing problems.  

That said, do they perform well as trickle filters?

Dave Johnson


Date: Wed, 23 Oct 2002 16:55:40 -0400
From: Thomas Barr <tcbiii at earthlink_net>
Subject: Re: Enough NO3?

> Can I assume that the extra fish load next month will help keep the NO3
> above 0 ? Suggestions?

I kind of doubt it.
It might if you feed well but there's a problem with using fish only for
adding a source of N for the plants when the plants use a good deal more N
than before.

It's somewhat like adding too many fish.
Too many fish will create algae.

Doesn't matter if you have 0.0 ppm of NO3, the plants will not be able to
get to it all before the NH4 fish waste or rotting food turns into NH4.
NH4 is like candy for algae and it really blooms heavy when even small
amounts of NH4 are present.
At low levels the plants keep it(NH4) very low. Most kits cannot test any.
As you raise this level, the NH4 is going to be available in larger amounts
and at some point that will be enough to get a bloom of algae going.

Fish only for a source of PO4 or NO3 is fine for the older lower light CO2
tanks but the recent advent of PC lighting and lots and lots of light has
caused a great increase in the amount of P, N, K, Traces, CO2 being used up.

So rather than adding more fish and risking NH4 caused algae, you can do a
few things:
1) Lots and lots of water changes every couple 3 days etc. This stinks. You
need to add nutrient back to the make up water etc.

2) Get a nice wet/dry filter which is great for turning NH4 into NO3
quickly(one reason I suggest folks with high fish loads to use these-better
bacteria than algae)

3) The most common solution is have a moderate fish load and supplement or
"Top off" the nitrogen needs of the plants with KNO3. This takes out that
very pesky NH4. It adds the most practical form of Nitrogen you can use
along with the K+ which is almost always a good nutrient to add a little
extra of.
So you kill two birds with one stone.

If you plan on over stocking a plant tank, get a nice big wet/dry style
filter. An added benefit of moderate fish loads is that the O2 often does
not fall below saturation during the nighttime. So it's always over 100%.
All the filter/airstones in the world will not do that. But as long as the
O2 is up at least in the 85% ranges most of the time folks are fine for a
low O2 reading. But 120-150% during some point of the day seems to be good
for plants and reduction of algae.

The extra fish and all the extra food waste consumes the O2. O2 levels will
be lower depending on how full you pack your tank. Less fish will give less
O2 loss but at some point you get too few fish and having some is good for
the source of NH4 in small amounts, just not larger amounts. So a nice
balanced fish load is perhaps the best long term solution for planted tanks.

For a 55, I'd add 1/4 teaspoon and that should yield 4-5ppm of extra NO3
each time you dose. You might want to add that 2x a week.
You'll be out of PO4/traces next:-) Make sure to add enough of those and
keep up on DIY cO2.

Many folks find NO3 and CO2 are the two most problematic nutrients in a
plant tank. Adding KNO3 and doing large weekly water changes takes care of
most issues. Change the DIY bottle often weekly etc will also make the CO2
more stable. 

Regards, 
Tom Barr


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