After a discussion here about a month ago ( where Physan 20 was mentioned) I ordered some. I've used on trays with lachenalia and hippeastrum seedlings. Initial I sprayed test areas but have now covered all of the algae covered areas. It had no negative effect on even the youngest Lachenalia seedlings ( the Hippeastrum hybrids were older and much larger). I didn't do a drench just used a spray bottle to soak the algae. I did mist the seedlings slightly just to get the chemical off of the leaves, but not enough to wash it off the top layer of the trays. I've had algae issues in the greenhouse every year due in part to our humidity and part to moisture retaining soil mixes. Even the mostly coarse sand seed mix I've made will get algae at some point. It seems to work quickly without negative effects. Tim Chapman > Do you have any experiences with seedlings ?? > > Roland >