I would think so, more surface area = more transfer, evaporation, area for sunlight to heat.There is a small strip of land only around 6 feet wide or so, between the house and brick fence. It stays pretty shaded, so I might try that.
This is probably a stupid question, but doesn't depth also affect temp stability? That might be another problem with the kiddie pools. But I liked them because they had a larger surface area, so more room for apisto territories, and I mgiht be able to divide them into 2-4 sections once they started pairing off.