how much K should i add to my tank?

[jon]

hi

how high should my level of K be in a 3 feet planted tank?
i've heard high levels r beneficial for plants.

im using Seachem's Flourish Potassium now.

jon.

[sherchoo]

I was dosing with 20ppm of K which had great results.

[tawauboy]

you'll need to dose to achieve 20ppm per week.

[M0rph3us]

http://www.csd.net/~cgadd/aqua/art_p...osage_calc.htm

[Nicky]

Hi,

I think for those who experience 'good growth with K', there are more to it than just K. My own experience of adding 20-25ppm of K (with all else remain constant) resulted in some plants dying. From the various postings, it seemed that K, Ca and Mg (and maybe others) have some form of linkages such that too much of one will limit the uptake of another.

So I think it is more than just K that makes the different.

[vinz]

Nicky,

Of course. K only helps if the tank is already more or less balanced. No point adding K to improve photosynthesis (and other things) if the plants do not have what is required for photosynthesis in the first place.

K is not a magic bullet.

[sherchoo]

But there was some discussion whereby with added dossage of K, plants exhibited some Ca deficiency. Seems to be the same in my tank. Look up the previous discussion for more info.

[jon]

thanks for all the help

i suppose i'll have to buy a tester for K as well eh?


jon.

[Allen_1971]

unfortunately K test kits are not available... at least not to the common hobbyist.

[kwangjw]

I'm using Seachem Flourish too.
The instructions say 1mL for every 40 L to give 1mg/L.

How do I translate 1mg/L to ppm to achieve the desired 20ppm?

Thanks.

[chongj88]

----------------
On 2/6/2003 7:50:53 PM

I'm using Seachem Flourish too.
The instructions say 1mL for every 40 L to give 1mg/L.

How do I translate 1mg/L to ppm to achieve the desired 20ppm?

Thanks.


----------------

1ppm = 1mg/l. I assume you also mean Seachem Flourish Potassium (there is also another product called Flourish and its recommended dosage is way less than 1ml/40l).

[kwangjw]

Thanks. Yes, I'm using Seachem Flourish Potassium.

So, I have potentially been underdosing by 20 times.

[PeterGwee]

Its too expensive to dose K using seachem potassium...Maybe you can have a go at Dr. Mallick K2SO4 powder....more economical.

[tawauboy]

----------------
So, I have potentially been underdosing by 20 times.
----------------

do you have k deficiency, that is pinholes on leaves?
if not, you need not dose k.

[kwangjw]

Tawauboy

No pinholes that I have seen except holes on the old leaves (right at the bottom) of the Hgyrophila Difformis. My Echinodorus Horemanni used to develop transparent patches on the leaves but it is ok and growing well.

The reason I'm dosing P is the bubbling I used to see in the 1st two months has stopped (this tank is coming to 8 months now). Some of the plants I have bought (glosso, e.tenellus has very little growth).

I'm just playing with fert, lights, CO2 now. I don't have test kits, so this is just a trial and error exercise.

[tawauboy]

what other fertilizer do you use?
what is your fertilization regime?

does your tank bubble the first few days after every water change?

[kwangjw]

I use:
ferrovit (Fe) at 1/2 dosage recommended on the bottle (afraid of algae).
seachem trace - as per instructions on the bottle
seachem flourish (K) - now at 10 ppm twice a week


At 20% water change which I do weekly, no difference in bubbling.
Adding more K seems to help a bit (can see it underside of leaves for the R.Rubin) but this really pales in comparison to when it started. Also the vals are kind of kinky but some of the newer leaves seems to have less kinky growth.

I did pull out some plants and the JBL fert did get into the water column at least 4-6 times... so not sure if the substrate is still effective.

[PeterGwee]

Hi kwangjw, might want to look into the Ca & Mg department....maybe even N & P unless you have very low bio load.

[sherchoo]

Kwang,
Care to share what is you pH/kH/CO2 level?

I seems that the load is on the moderately high with 12 tetras in a 30g tank. Should not be N or P.....

[kwangjw]

Sherchoo

Looks like have to go buy some test kits after resisting for so long.

Anthony