To be honest I assumed that I have 3 IPAs they would all be at the same temp. I didnt think about if I brew 3 batches ( one each Day) that the temps would need to be different? dont I want to keep the temp between 66 and 68 through the whole process.
And rain away, I need to know all this before I screw something up.
No rain here, just trying to help you avoid a decision you'd like to have back.
Let's assume that you're brewing a beer whose fermentation temp you want to keep at 66 degrees (common temp, btw). If you kept that fermenting beer in a room at 66 degrees, the actual temp of the fermenting beer will likely be between 71 and 76. Yeast express different flavors depending on temps, and if you let the beer warm too much, you'll likely get flavors you weren't intending.
So, you need to control temp. In a single-fermenter approach, you'd put it in a fridge or freezer, put a heat mat around it (so you can raise temps at the end to let the yeast clean up after themselves), attach the temp probe from the Inkbird to the side using foam to isolate it from ambient, or use a thermowell, and then you'd be able to control the temp to within a degree. When the fermenting beer got too warm, the fridge or freezer would go on. When temps were too low or you wish to raise it up, the heat side of the Inkbird turns on the heat mat.
When you have multiple beers from different days in the same ferm chamber, they're out of step as to the yeast's exothermic reaction. With my 2-batch approach, here's what I did (not saying you should do this, it's just an explanation so you can understand the logic):
I brewed Batch 1, put it in the ferm chamber, attached the probe, and let it go, holding temps where I wanted them. I brewed another batch a couple days later, after the krausen had fallen on Batch 1; I moved the temp probe from Batch 1 to Batch 2, and then used a second Inkbird to control the heat mat on Batch 1. Since Batch 2 would have more exothermic activity, the fridge would cool it down when needed. Problem was it would cool Batch 1 down too much, which is why I had the heat mat on Batch 1 controlled by the second Inkbird.
Thus, when Batch 1 was cooled too much by the Inkbird/Refrigerator responding to Batch 2's heat, the second Inkbird would add heat to Batch 1, keeping it where i wanted.
I think you could do something similar with a freezer with three batches in it, but you'd need 3 Inkbirds (probably) and 3 heat mats, and then just keep moving the probe controlling the freezer from batch to batch. Not sure if it would work on batches brewed 3 consecutive days, I'd have to think about it.
Now, having said all that--and hopefully it makes some sense--you've only brewed 4 extract batches, no all-grain as of yet, so you still have some process issues to iron out. I'd be focusing on getting the beer to be good, one batch at a time, before trying to do multiple batches spread over several days. If you try to do that right off the bat, and the beer isn't quite right, is it because you haven't nailed down the all-grain process, or because you haven't figured out the temp control issues during fermentation?
One last thought: you might consider 3 small fridges instead of one larger freezer. That way you control each individual batch as you see fit, and can alter temp profiles and such as you wish. They're not as cheap as a freezer if you buy new, but you can find them used on Craigslist. If it were me, I'd rather have 3 separate ferm chambers as they would give you the greatest flexibility--and would probably take up about the same amount of space.
But--one thing about homebrewing is we all get to make the choices that work best for us, it's supposed to be an enjoyable enterprise. Take the above as suggestions, and enjoy the journey.
