saulat

Hi,

I posted looking for help on fertilizer not too long ago. I followed a suggestion and ordered KNO3, KH2PO4, and CSM+B. Looking at an email from Alan from aquariumfertilizer.com he talks about this

AquariumFertilizer.com's PMDD Formula:
1 Part KNO3 1 Part K2SO4
1 Part MgSO4 1 Part CSM+B

What am I supposed to do with the KH2PO4? Why didn't I order the K2SO4 and MgSO4? I don't think I need the GH booster, my tap reads at about 150 ppm GH, and about 40 ppm KH. Alan also states that the limiting factor is supposed to be phosphate (he put K2HPO4 next to the word, not sure if he meant KH2PO4 or not) when following the PMDD method, why would I be adding the KH2PO4 in this case? Can I mix these together or do I make one solution of KNO3 & CSM+B and then one solution of KH2PO4? Do I have what I need to cover fertilization for NPK and any other nutrients I may need?

I finally got my pressurized Co2 going yesterday and am almost out of my store bought liquid fertilizer. Thanks for any help. Oh and here is my previous post http://www.aquaticplantcentral.com/f...oduct-buy.html


Looking here it has a dosing suggestion. http://www.bestaquariumregulator.com/dosing.html
Do I need to dose the Iron even though I am dosing the Plantex CSM+B? Of course I don't like this as I like the idea of dosing daily amounts.

Seattle_Aquarist

Hi saulat,

You have everything you need to do Estimative Index (EI) dosing. Why not give it a try, it has done wonders for my plants. BTW, MgSO4 = Epsom Salts available at your local pharmacy for about $4 per pound.

saulat

Sorry, guess I should look at the stickies a little better next time. Think I have found what I need. Now if I can just get the Co2 set how I want it.

Thanks

Philosophos

I do a lot of fert tinkering just for the love of it; usually I barely get through a batch before creating something new to play with. If you end up getting stuck, or hitting weird precipitates, let me know.

-Philosophos

saulat

Sure, I do have a question. Is the MgSO4 for adding magnesium and might I need it when adding the Plantex CSM as it has 1.50% Magnesium? I think I will start adding the dry chemicals tomorrow, I am already in the habit of dosing 3x a week.

Philosophos

CSM/CSM+B has so little Mg in it that I don't even account for it when I mix ferts. Lets say you do 10g/L as a solution for CSM; that's about 150mg of Mg. 150mg of Mg is about enough to dose a 5 gal for one week.

-Philosophos

saulat

I was wondering would I still need to add Mg due with my GH and KH? Also, according to my test strips I have around 20ppm Nitrates from my fish population. Would adding the KNO3 pose a problem? It seems like without it I'll be lacking K but with it I risk pushing the limit with NO3. Here are my water readings.

Ammonia - 0
Nitrites - 0
Nitrates - ~20
KH - 80ppm or 4.5 dH (steady here for about 2 months)
GH - 200ppm or more (has always stayed this high from tap water)
PH - 7.2 (was steady at 7.4 until I began the pressurized Co2 two days ago)
Co2 - Unsure, still setting up how I want it and letting the system stabilize

I guess I have another question as well. By adding phosphates don't I invalidate the KH PH Co2 relationship. Do I use observation to estimate how much Co2 to inject into the tank?

Seattle_Aquarist

Hi saulat,

I would not add KNO3 at this time, the I use a target level for nitrates of 10 - 20 PPM so you are currently at the high end of the range. As your plants grow, the PPM level with probably drop and you can start dosing your KNO3 at that time.

You may not need MgSO4 at this time either. I would probably wait and see how the plants grow, watch for deficiencies, and then dose Mg when it is needed. If you tap water comes out with a KH and GH like your tank tested, and you do 50% water changes weekly, you may not need to add Mg ever! I wish my soft water was more like yours!

As for CO2, I would invest in an inexpensive "drop checker" and mix of a 4.0 KH indicator solution to use in it. I find that it is the easiest way for me to monitor my CO2. I am not aware of phosphates affecting KH or PH readings.

Philosophos

I guess I take the opposite approach. I load in the K2SO4 and MgSO4 right away into a liquid mix; I find my tanks pack out fast. The real questions would be plant density, light level and tap water; low light and a medium density tank don't require 20ppm NO3 dosing/wk. I usually just dose the same mix as in high light, but half as frequently.

Get a water quality report; it's always nice to know what's in the tap water that goes to your tank. I've got hard water, but Mg from tap is only 2.5ppm.

-Philosophos

deicide

I suggest this approach as well; however, with one minor change. Since your GH is fairly high I woluld hold off on any additional Mg dose unless your start seeing Mg issues or until you get that water report which will either confirm no additional Mg or that you need to add. For the time being just rely on the little that CSM will be adding.

For K, add enough to give you 25~30ppm in the 'changed' water at WC.

You need to increase Co2 as well.