are you hand pollinating or vibrating the clusters?
Do you know the concentrations of N, P, K, Ca?
When my nitrogen levels are higher vs Phosphorus, it seems like I get more blossom drop? I don't know that for sure, or have an exact ratio its just something I've observed of late.

Grizzman,

I run an oscillating fan about 8 hours a day, but also vibrate the cluster in the morning and evening. As for the NPK, I'm using the old version of Tomato-tone, dissolved in water with an ounce of fish emulsion per 10 gallons of water. I also add a multi-vitamin every two-three weeks to cover the micronuit needs.

More than likely, I'm (over) micromananging the plants. I suspect that in a garden, in summer, blossoms drop all the time but because I do not inspect each plant 2-3 times a day, every day, I don't see it.

What I probably need to do, just to satisfy my curiosity, is to get off my butt and take light intensity readings every hour from sun-up to sun-down. That would at least tell me the moles per day I am getting, though I'm not sure how important they are when it comes to converting blossoms to fruit. The plants are Legend tomatoes, bred for the lower-light, cool conditions of the Pacific Northwest.

Mike

Dont you need soil with microbes to break down Tomato-Tone into a usable state? Its an organic powdered fertilizer. I think at this stage you need to cut the Nitrogen and only feed P & K to produce fruit. I could be wrong however but thats what my understanding is. In soil grown plants people use things like Alaska Morbloom which is a 0-10-10 formula.

alex,

From talking with the people at TT, some of the nitrogen does not break down, which is fine with me. When the plants were real young, I added fish emulsion for the Nitro and they grew great, even in water. They still are getting taller and staying green, with lots of new shoots and blossoms, just no fruit.

I do have some fruit and bloom nuits that I will add the next time I replenish the water level.

Mike