[RayR]

Originally Posted by Cole_Robbie

Well I guess we're going to find out, because I am sick of smelling like rotten fish. I had tolerated it because I thought it was good fertilizer. It certainly seems popular.

Your not supposed to fertilize yourself with fish hydrolyzate
Fish emulsions smell worse to me.
I never had a problem with the smell after diluting and applying it. The microbes degrade the odor pretty fast.

Originally Posted by Cole_Robbie

This stuff should be called 'Bag-O-DampnOff:' http://www.menards.com/main/outdoors...88-c-10116.htm It seems like everything I plant in this mix dies. I even lost cabbage plants to damping off with it.

Now you can't blame the Pro-Mix without eliminating other sources that may be the source of whatever pathogen is causing damping off. You can get damping off from spores in your water as well as the air. Your greenhouse itself may be harboring the spores.

Originally Posted by Cole_Robbie

I guess chemical ferts are the large-scale commercial standard because of price? I use so little that I can't tell the difference in cost.

It's always easy to sell something because it's cheap and easy. Of course they never do explain the downside that can happen later on. But they are always ready to sell you other chemicals to try to correct what the others caused.

Originally Posted by Cole_Robbie

My greenhouse plants get cold at night, into the 30's. Everything seems worse when the weather is colder, and I don't have sunny days. Today is sunny, so the greenhouse temp is in the upper 80's. Maybe it is my cold nights that make damping off so much worse for me.

That's what bothers me, those wildly fluctuation temperatures. Cool and wet conditions select for the pathogens and decrease the biological activity of the good guys. The bad guys are parasites, they aren't interested in your fertilizer for food, they need a living host to survive and reproduce. Cold soil conditions also weakens the plants own biological activity.

Originally Posted by Cole_Robbie

Regarding hydroponic plants, they tend to get pythium in the form of root rot. The solution is easy - just aerate the nutrient solution better. I am hoping using more perlite in my mix can accomplish the same thing.

The Pythium that causes root rot in hydroponics is the same Pythium that causes damping off in soil. The big difference is the Pythium is hydroponics gets a free ride around the reservoir making it easier to find its victim without much resistance by other microbes.