Merit 75 for root aphids in ebb and flow

I just added Merit 75 @ 1 Teaspoon for 10 gallons last night to my reservoir with regular nutes. Plants are still pretty small and in veg. I cant seem to find out how long to keep it in there for. Plants only get watered 1-2 every 24 hours for 15 minutes. I also poured in solution from the top to make sure it all got drenched.

Thanks

Bump, anyone ?

Looking in tray today 24 hours later I could see hundreds of dead ones near the drain. Before they would all crawl back in the pots so it looks like they got pretty nuked with this stuff so far. Want to make sure I do enough but not too much.