APD/RAFP and Adding Nitrate

Subject: Re: Technical content of RAFP vs APD
> Fri, 15 Mar 1996 George Booth wrote:
> <<[...] Since all the
> "experts" have gravitated to the APD in the recent months [...]
> We can have just as "meaningful" discussions in the newgroup as 
> here.>>
> We're all obviously worried about the radically higher ratio of 
> grain on the newsgroup, but I think George has an excellent poin
> existing APD members who are able will make an effort to have a 
> the newsgroup, then we can significantly affect the flavor & hef
> discussions.  

I am "able" I suppose, but feel I do my part helping beginners out 
already.  APD is a place that I enjoy because it is a place that 
_I_ get something by sharing with other advanced level hobbyists. 
 I'm just spread too thin, in a number of other directions, many 
of which are for the benefit of beginning aquatic gardeners for me 
to put the extra effort into weeding through everything on the 
newsgroup on a regular basis.  

I have contributed to rec.aquaria from time to time, and I will do 
the same with .freshwater.plants ocassionally, but it will 
definitely be on a time-available basis, which means not often.


Subject: Re: adding nitrates
> >I have OFTEN seen cyanobacteria present even with high nitrate
> >levels.  I also am not sure it's a good idea to suggest adding
> >nitrate to the average planted tank containing fish.  In a tank
> >without fish, it is certainly possible to end up with a nitroge
> >deficiency. But in tanks with even a fairly light fish load, th
> >is usually plenty of nitrogen available to the plants. 
> Maybe my light fish load is VERY light, or I do not feed enough 
> density is relatively higher), but I often observe nitrogen defi
> know this because the duck weed (indicator plant)looks pale and 
> reproducing. After adding 1-2 grams of NaNO3 (Nitrate of Soda, f
> store), the plants perk up, including the duckweed. BTW, 1/8 tea
> approximately equal to 1 gm and yields a concentration of 1ppm i
> I also think that adding the nitrate will help consume excess ph
> (but it will also consume Potassium, and everything else, but it
> Keven has already taken that into consideration.

I know that this does happen under some situations, but almost 
always with experienced aquatic gardeners.  Most beginners just 
don't get good enough plant growth to be able to suck nutrients 
out this quickly.  Since I deal so ofen with advising first time 
aquatic gardeners, and alarm bell rings when I hear someone 
suggesting the addition of nitrate. (or phosphate containing "pond 

I have _never_ had a beginner come to me with tales of woe about 
how he can't keep his nitrate level up, the reverse is the norm.
> >recommending a nitrate level of 10ppm is asking for trouble.  S
> >people, with other parameters just right, get away with it, but
> >I'm fairly certain that it doesn't contribute to good plant gro
> >as long as ammonium is available, and it _can_ cause algae 
> >problems.
> I think that a few ppm of N is plenty!

I would suggest that if you have _any_, you have pretty good proof 
that your nitrogen levels are high enough.  Otherwise, the 
ammonium would have been used by the plants before it ever had the 
chance to be converted to nitrate.  

Obviously if you have _no_ measureable nitrate, you have to guess 
whether you have (buy) luck arrived at the optimal amount of 
nitrogen, or if your plants might not do a little better with the 
addition of a little nitrate.  But again, IMO, if you can test any 
nitrate, I don't think your can have a deficiency.

The other problem I commonly see is beginners who have a nitrate 
kit, but not a phosphate kit.  While I suggest they get both,  I 
can almost lay bets that if they tell me that their nitrate level 
is high, the phosphate level is high too.  This is because in the 
average fish-and-plant community (which I'm pretty sure accounts 
for the bulk of planted tanks) the nitrate/phosphate is coming 
from feeding, or worse, from mis-use of various "additives".

> >That's one reason that I wouldn't call the DIY fertilizer "poor
> >man's Dupla drops"... Dupla drops do _not_ contain nitrate.

> How about "lazy aquarist who starves his fish drops"

That works, except LAWSHFD is a pretty long handle ;-)

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA