How do I transition to Thermal Aquatuners without any oil? (Berry Blossoms dying)

In Oxygen Not Included I have a problem that I am running out of cool water (below 86 F) for Berry Blossoms, my main crop at cycle 45 or so. I have plenty of warm water that I use for my latrines, but that water is at 100F or more, so I cannot use it for Berry Blossoms.

I know a Thermal Aquatuner can be used to lower the temperature of the water, but it will overheat unless it is cooled and the only way I know to cool it is to immerse it in oil, but I am nowhere near the bottom of the map so I have no access to oil.

How can I cope with this problem?

Also, I have not found an ice biome yet, and even if I did find one, my previous experience is that it takes a long time to build a radiator in an ice biome because it is far away and the dupes do not like the cold. Also, the amount of wolframite you need for the pipes is crazy and the amount inside the ice biome is nowhere near enough. If you use granite, then the dupes have to travel a long distance to go get the granite, so basically by the time you get the radiator built you are dead. Also, I would have build an incredibly long pipe to reach the ice biome which would take a long time.

You can use any liquid for that purpose, not just oil, water or polluted water is fine. The key is to submerge an aquatuner completely, two tiles high.