[Capt.]

I'm trying to get my tank's fertilizer schedule just right. Looking for some suggestions on what and when to dose. Here's what I have now:

72 gallon tank
80 watts normal fluorescents & 55 watt power compact, approx 1.9 wpg
Flourite & Profile Aquatic Soil substrate, approx. 3.5" deep average
Pressurized CO2, approx. 25 ppm

Dry ferts: MgSO4, KNO3, KH2PO4, K2SO4
Liquid: Flourish for the traces

 

[plantbrain]

Water change:
50% weekly
The day of the water change, right after add:

Add KNO3, 1/2 teaspoon
Add 1/8" of KH2PO4

Add 15mls of traces the following day.

On 3-4th day after the water change, dose the KNO3/KH2PO4
The following day, add the traces again.

Water change at the week's end and repeat.

Regards,
Tom Barr

 

[S]

I follow a similar routine on my tank but I dose the TE each day. Does that make a big difference?

 

[Aaron Ivers]

Tom,

Would you care to explain 1/8"? I read this on one of your posts to the APD as well and assumed you meant teaspoon, but now I'm unsure.

If it does mean teaspoon, by my calculations it would mean ~2.2:1 N to P ratio (or 3.2:1 NO3 to PO4 ratio). It seems like that's pretty rich in phosphate...

Thanks,
Aaron

 

[Capt.]

Thanks for the reply Tom. Have a couple quick questions about your schedule.

1. By the APC Fertilator calculations, you are suggesting I add approx. 7.2 ppm of nitrates, 1.84 ppm of phosphates, and 5.3 ppm of potassium. I thought potassium was supposed to be higher than nitrates? Does that not matter much?

2. You don't think I need to add any MgSO4 or K2SO4?

BTW my tap water has a KH of 3 and I can't remember the GH off hand, I can check when I get home tonite.