Rust fertilizer burn or what

Not sure what this is I kind of feel like it may be rust and I want to try to treat it with sulfur but I don’t know what to do so any advice is gladly welcome???

Temp 70f to 75f.
PH high 7 to low 8.
Fertilizer used superthrive and fish emulsion.

pH should be between 6.3 and 6.8.

The plant is far too young to feed anything. Feeding should be based on runoff PPM levels. Depending on what soil you are using, you may not have to feed anything for 4 - 6 weeks. Begin feeding when runoff PPM dips below 1,000.

Sulfur is a secondary micronutrient. It is unlikely that it is a problem, particularly when you are in new soil.

The seedling will likely grow out of whatever is causing the discoloration.


Ok so forget about fertilizer for now and focus on the total dissolved salts from the runoff. Should I be taking my pH reading from the runoff or from the actual soil itself?

pH both what is going in (after you have added nutes) and the runoff as well. Checking the runoff will give you an idea of what is going on in the soil. Runoff pH should remain fairly stable until you start getting a buildup in nutrient salts.


Thank you you rock brother!

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Welcome. Happy growing.

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