So I am on day 10 in the FV of my second brew.
I am doing a Cooper's Pilsener, 1Kg LDME, 300g dextrose, and 13g bagged Saaz hops added on day 5.
I aerated the heck out of the water. My FV is sitting in a 100L tupperware box half-filled with water that I got down to 18 degrees C. The A/C is blowing on the exposed water and keeping the temp at 18.x.
I am really pleased with how stable the temperature has been and fermentation has been effective. I pitched at 21, then lowered to 18. OG was 1044, and last night (day 9) SG was 1009. Also, I rehydrated the yeast from the 7g packet.
It even tastes like a hoppy lager. Next time I'm doing an IPA recipe (probably a Cooper's, as that's what is available here in Singapore).
Thanks for the help! My takeaway is that this massive heatsink approach works well.