Fertilizers in the filter

[mmohamma]

Hi everyone,

I finally redesigned my 65G tank 3 weeks ago with lots of new plants. But some of the leaf tips are starting to get yellow. Based on the postings on the web, this usually means lack of nitrate.

here is some info about the tank:
Substrate is Eco-complete, covered with black sand.
During the setup, I added some Osmocote plus fertilizers, and 3-4 root tabs (which I wanted to get rid of).
I'm injecting Co2.
I'm also dosing Nitrate and Phosphorous (5 ml) each day.

This is only happening to broad leaf plants like Ludwigia. Cabomba and Hydrocotyle look pretty happy.

I was thinking of adding some Osmocotes (in a bag) to the canister filter and let it do the job. Has anyone done this? naturally, I have to do something to avoid it getting tangled in the propeller. What do you guys think?

Thank you,

 

[ZxC]

Nope, don't do that.

Instead:

Ensure pH is dropping a full 1.0 from non-CO2-Injected to CO2-Injected water.

Test pH before CO2 comes on for the day, then test again during the last hour or so that the CO2 is on, make sure the drop in pH is 1.0 up to 1.3.

Next, you'll have to dose more than just NO3 and PO4.

Pick up:

KNO3
KH2PO4
K2SO4
CSM+B

if your pH is above 6.5 pick up:
11% DTPA Iron
or
Flourish Iron

Continue to use Osmocote+ root tabs if you want.

I would start by dosing:

1x per week (after a 50% + water change)
15ppm NO3 - Use KNO3 for this
5ppm PO4 - Use KH2PO4 for this
15ppm K - KNO3 + KH2PO4 will give you some, use K2SO4 for the balance

Then 3 x per week:
CSM+ B - Target 0.15ppm Iron

If pH is above 6.5 and you use 11% DTPA Iron or Flourish Iron, target 0.15ppm Iron 3x per week on top of the CSM+B dose.

This required a 50% or greater water change per week.

You can find all these on amazon / GLA (if you're in the US anyway).

Buy a cheap pH pen that comes with a calibration function and solution plus a cheap 50 gram scale with 0.001g accuracy that comes with a calibration weight.

use this:

https://rotalabutterfly.com/nutrient-calculator.php

to determine how much you will have to dose.

Insert your actual water volume - not your tank volume (estimate this).