Hi Rimmer, Firstly Daconil is a fungicide. If you are using a liquid or flowable formulation there are both oil base products and water based products. If you are getting phytotoxicity it is probably the oil carrier. It will be related to either the concentration of the solution or rate of application, especially on tender or young or sick plants. (Did you give a quick misting or did you apply to a point of run off?) Daconil is a great fungicide if you need one. Don't give up on it. If you need to use it in the future and are concerned about burn, apply it in the evening or on a cloudy day. If it's under lights turn the lights off for a period of time. Same thing for the insecticide Merit or Admire. There are many different formulations of this insecticide. It's hard to say if the rate is OK. These products are used as a soil drench in many commercial situations. It is possible to damage the plants with over applying a drench as well. It is a systemic and is taken up by the plant. The plant has to deal with the chemical in its system. I hope this helps you out . Brad. Ontario Canada, Zone 5b Warm 0 C/32 F and 6 more inches of snow today. aphid control was Cyanella seedling advice Rimmer (Tue, 18 Feb 2014 09:56:18 PST) on advice of someone directly in hopes of ending the aphids i have soaked all my pots with a Merit based insecticide (Bayer Tree and Shrub) - 1 tsp per 1 quart, is this too strong a solution? the aphids came with Oxalis callosa and O. obtuse - i tried Daconal which scorched the Oxalis leaves under the T-5 lights so i used the insect soap which does very little.