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Re: Nutrients + Equilibrium?

Susi Barber wrote:
> I've been following Tom and Roger's posts with great interest re dosing with
> KNO3, K2O4, KH2PO4 - was wondering what tank size the 1/4 teaspoon of KNO3
> referred to?

If you're refering to my 1/4 tsp of KNO3, that's per 40 gallons and
dosed twice/week.  I used that rather experimentally and the results are
great in some cases, not so great in others.

> So in total, I must have added about 2 tsp minimum of KNO3 to
> my 25 gal tank - was it just starving, as I did it over several intervals
> with a couple of hours inbetween, and it all got absorbed instantly?  the
> plants don't look too much different, just redder from all the P!

Could there be something wrong with your nitrate test kit?  Using the
dosing measures in Neil Frank's article (at the Krib) 2 tsp of KNO3 in
25 gallons of water should give you something closer to 70 mg/l NO3 than
to 7 mg/l.

> I tend to have P levels much higher than N, btw about 1 and 3 by the end of
> the week; N is about 3-6, so it could go up a little more.

I'm a little confused by this.  Generally you want N to be quite a bit
higher than P.  If P is normally higher than N then you probably
shouldn't dose P.  Just N.

I would be more conservative with my dosing, as overdoses can be hard to
clean up.  Further, if you make the right changes then even small
changes create noticable effects.  When you experiment there's usually
no need to go overboard.

> The next question is what do I do about using Equilbrium, which I have been
> using to provide traces and also to get a GH of 8-12 in different tanks

<snip -- I can't help much with the trace mix>

> Equilibrium has potassium 18.9%, magnesium 4.3%, calcium 2.7%, Fe 0.47%,
> manganese 0.08%.
> The potassium I was adding in a big way in the liquid form, less meant holes
> in leaves, so it was being added only to just over the minimum (40 ml per
> day in 25 gal tank).

The instructions on the bottle would call for 2.5 ml / 25 gallons to get
1 mg/l K, repeated 2-3 times a week.  You're adding enough to boost the
K concentration by 112 mg/l per week.  And that's just from the Flourish
Potassium.  The Equilibrium would add quite a bit as well.  Your plants
don't need that much potassium.

> Magnesium and calcium are also being provided by
> dolomite; so I guess all the Equilibrium is really adding is the iron and
> manganese, so if I use a trace mix instead, that should make it
> unneccesary.......sugar, and I just bought a big bucket of the stuff for $75
> a couple of weeks ago!!

The Equilibrium is still adding the potassium, magnesium and calcium
even if you don't really need it.
> Other info - my tap water is very soft, pH about 5.5, no KH or GH or
> calcium, so I add baking soda for KH to about 4, Equilibrium as above, and
> dolomite to give me 40 mg/l of calcium, with very heavy feeding for the N
> and P (4 times a day in my big soft water tank, 5-6 times a day for the
> guppies, liberal amounts).  I found I had to add the K to balance this.

Susi, I think you may take the prize for complicated dosing schemes.

If you want to work mostly with Seachem products, then the product
labels lead me to believe that you should use Alkaline Buffer to get
your KH (drop the baking soda that you have been using), then add enough
Equilibrium to get GH to balance the KH.  Don't use the Flourish
Potassium unless there's a need for it, as the Equilibrium carries a
heavy load of potassium.

The Seachem products seem to be pretty light on calcium, so it might be
a good idea to use Alkaline Buffer and Equilibrium to get about 2/3 of
the GH and KH that you need, then bring the GH and KH up the rest of the
way to your goal by putting a calcium carbonate source in a mesh bag in
the tank.  Oyster shells, marble chips, crushed coral and a lot of other
things are adequate sources of calcium carbonate.  Don't use dolomite
chips, as they will add more magnesium along with the potassium.  Remove
the mesh bag if the GH gets higher than you want it.  

For a simpler and less expensive approach you can use Morton No Salt
(about 96% KCl) to add potassium and dolomite chips for calcium,
magnesium and alkalinity.

I add 1/4 tsp of KCl to 35 gallons of water to get about 6 mg/l of K,
then use that for all my weekly water changes.  KCl should give you 34
mg/l per teaspoon in 25 gallons of water.  Use a mesh bag for the
dolomite chips.  Oyster shells, crushed coral and marble chips aren't
good for this, as they don't add much magnesium.

Your water parameters will be a lot more stable if you do small (say
10-20%), water changes every week or so.  If you have to do all that
dosing then big water changes seem like a bad idea.

Roger Miller