How much seaweed?
 

Can too much seaweed harm plants in s/h? I have Neptune's Harvest (stated on the label to be 0-0-1). It says to use 1 tbsp per gallon. I have been diluting this in half just to be safe. What is optimal? Amount per gallon and feeding times per month?

Half the recommended strength is just fine IMO. It's always best to under fertilize rather than over fertilize. I learned this the hard way when I was trying to force my plants to grow new roots with superthrive. The result of that experiment was brown unhealthy roots and deformed flowers. Less really is more. :twocents:

I could probably just add like 1/2 a tbsp of seaweed to my regular s/h msu fetilizer solution right?

Yes, you can add it to your regular fertilizer.

1) Seaweed extract, by itself, may have some nutrients in it, but it should not be considered to be a fertilizer.

2) Not all seaweed extracts are the same, and I know nothing about Neptune's Harvest, but I use KelpMax at a tablespoon per gallon with no issues.

3) Excessive treatment can be detrimental to the plant, but I believe that is more related to frequency than dose, within reason. The plants' response to the hormones takes about 2-3 weeks to go through its full cycle, so I'd not treat any more frequently than that - personally, I prefer a month.

Ah! Very good information here!

Thanks for the advice! :)