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You can draw any curtains/drapes in the room during the day to keep heat down.
You can run a fan across the top of the tank to draw the coolness into the water column.
Please do not add ice cubes. This can not only change the temperature too quickly, it can also mess with your water parameters as this is now chlorinated water.
75: blood parrots, featherfin cat, emperor tetras, turquoise rainbowfish, BN plecos, japanese trapdoor; 46: WCMM, gold inca snails, ghost, bamboo & amano shrimp, kuhli loaches, rummynose & ember tetras, endlers, platies, flame gourami, guppies; 16: pygmy, peppered, loxozonus corys, otos, assassins, RCS ... ~ Research PRIOR to purchase.... ~