Chuck wrote: Hi Jaime, You have an interesting system. The water temp, however will probably skew your results. They will be far earlier than otherwise. I also think you give too litle credit to the Wall O' Waters. I used a max / min thermometer a ciuple of years ago and found 10 -15 degrees of improvement, depending on how sunny the preceding day was. The water temp in the WOW is VERY significant as is the temp of your circulating water. The proximity to the Ocean will also raise night temps in most cases. ------------------------------------------- me: My hydroponic solution is outdoors in a 250 gallon tank and not heated. Right now at 8AM the air temperature is 47F but the hydroponic solution is 57F. It has warmed up dramatically the last week here. My plants get fed for 30 minutes 5 times a day from 10AM to 4PM. The thermal inertial of the hydroponic beds is not that high, they are 12 inches above the ground. I should stick the probe into the perlite early in the morning to see what the temperature is compared to the air. A 5F improvement is what I have randomly measured with my min max thermocouple probe. Also, by late April the Kotlas and Stupice are above the top of the WOW and need support. I usually have to remove the WOW before I want to so that I can tie up the plants and not damage them by removal of the WOW. The other unfortunate problem that I have is that my garden is at the northern side of my house and I only get 5 or 6 hours of sun a day. A couple of big redwood trees are in the way as well as the house. Time to get a chainsaw! (just kidding). Maybe I should consider an earlier feeding to "warm up" the roots of the plants at 5 or 6AM. Thanks for pointing me in a new direction! When I got tomatoes at the end of April at the beach, it was a "normal" spring, but you are right, it was much warmer than here in the hills. Still only a 5F improvement with the WOW and temps into the low 40s at 6AM. ------------------------------------ Chuck again: You might consider "Mountain Princess" and "Early Maturing Siberian" in your trials. I've had good results with both. I didn't particularly like "Sasha's Altai" and find "Dr. Carolyn", a sport from "Galina", to be more stable than it's parent. I'm trying "Clear Pink Early", "Early Wonder" and "Prairie Fire" this year. "Grushovka" is another long time favorite early variety for me. -------------------------------------- me again: I seem to have ignored determinate tomatoes for a long time now. I think my Green Grape may be determinate, it has been described both ways. I tried Oregon Spring a long time ago and did not think much of that species. Maybe I should try determinates for my early species since my goal is to get tomatoes early before the "regular" tomatoes start producing. Looking in my Seed Saver's 1999 Yearbook: Grushovka- pink-purple plum shape determinate Mountain Princess- red determinate from West Virginia Early Maturing Siberian- couldn't find this one I will save this information and give them a try next year. Thanks again for the information. I should sort out Sasha's Altai and Galina this year. Jaime (in the Santa Cruz Mountains of N. CA USA zone 15)