Hey all, I am about to start dosing the EI method (it seems less hassle) but I am worried about the lack of potassium. All the sites that gave EI methods stated that you got plenty enough potassium from your phosphorous and nitrogen compounds. Is this true? If I need to add more potassium later how can I tell that I need to add some. Yellowing of the leaves? Thanks all
EI dosing method question
- Thread starter Skillet_007
- Start date
easy way is to get the test kit. if you are worried you can add some. i have some fleet on hand just in case. with EI you dump a bunch of ferts in clear it out each week. unless you have a bunch of fast growing plants you shouldnt really run into a problem at least from my experience.
There is a EI calculator. It allows you to enter the tap water parameters. Gives you the amounts for different chemical nutrients. Breaks it down for every other day macro & mirco dosing with 50% water changes weekly. Gives you somewhere to start. I add only potassium sulfate. potassium nitrate would increase my already high nitrates. mgso4 is epsom salts from the store. Mono Potassium Phosphate is added minimally as the tap is loaded with 1pmm-3pmm depends on season. Great talking to you and Good Luck. Bob
Thanks so much for the info bob, you helped tons, and btw MGamer, I have bought some stuff from you in the past from aquabid and I might be pming you soon to see what else you have. Thanks for all the help, i'm going to get started right away.
I've never seen any signs if folks use EI for K+ deficiency.
Some went the other way and claimed too much K+ causes CA++ stunting in tips, however, this is due to poor CO2, not anything to do with K+ concentration or Ca.
The fact of the matter based on plant tissue %, you'd need 4x as much N for every mole of K+ before you'd run limiting for K+.
GH booster also has about 50% by weight K2SO4.
Those two alone provide a very large buffer of error for K+. Over time, the ppm's should build and level off, about 20-40ppm.
Adding more K+ will not hurt anything either, up to 50-100ppm ranges.
Most aquatic plants are fertigated with a hoagland's hydroponic solution, which is 230ppm of NO3, close to the same for K+,
http://fins.actwin.com/aquatic-plants/month.200201/msg01106.html
Paul did a nice study back around 1966 on this topic for aquatic plant growth and nutrient limitations.
You can see that the K+ is higher than anything else there.
235ppm.
1/5th is still 47ppm.
For N, it's a lot, about 42 as N-NO3, so converting to NO3, x 4.4.
180ppm.
Another good site and info for nutrients and soils:
http://www.soils.wisc.edu/~barak/soilscience326/hydropon.htm
I'm hardly telling anything new.
New to aquarist perhaps, but the ideas and concepts have been around in plant science and in the hobby(large water changes etc) for a long long time.
Regards,
Tom Barr
I spoke to Skillet at length about EI dosing. Gave him the calculated daily doses for his 120g. He is off and running with his 50% water change and dry ferts today and CSM+B tomorrow. Every other day dosing for 6 days, one day off and the wc to start it again. He has 20+ppm nitrates and will just do potassium sulfate, mgso4 and khpo4 to his well water along with the kh booster and seachem equalibrium to enhance his soft water. He will enjoy the extra change in his pocket and thriving plants.
well my mind screwed up.... all those dang fert names i mix them up at times. i was thinking of Potassium Phosphate<P>. should have thought Potassium Sulphate <K>
didnt help you too much on this one i got it wrong.
This assumes that there is actually 20ppm of NO3 in the tap
If not, things will not go well.
KH booster is not needed, GH booster is since it adds both Ca/Mg and K+.
All in one vs dosing a 3 things separately.
Cost is not a factor either, GH booster is 2-3$ lb.
I would be very careful in assuming any ppm's from tap or certainly te4st kits without using a high grade test kit(Lamotte etc) and a couple of reference standards to compare the NO3 reading againist, otherwise, this is just a guess at best.
You are not going to get around that.
The management is fine if the NO3 in the tap is 20ppm, but think about it, a 50% water change adds only 10ppm per week of NO3.
With CO2 and dense plant biomass, that will be gone unless they feed a lot to fish, have sediment based ferts etc in conjunction with(not a bad idea here and in most cases)
Regards,
Tom Barr
OK, I am going to take a well water sample to my fisheries class tomorrow. We us Lammotte tests up there. I will check and see how much NO3 I have in my tap for sure. I will also bring my aquarium water. I am using Seachem Equilibrium as a GH booster for now, had no idea that it contained K. I will hold off dosing K2SO4 for potassium since I very well now see that I am getting plenty of K through my gh booster, KNO3 and KH2PO4. (This is right, right?) Thanks for all the help guys.