new sump= Major problems

[chevyjaxon]

i went to Big als and bought a new sump made by megaflow this week. cost $400.00. ok so heres the deal bought the sump to quiet things down a bit now things are pretty quiet but my temperature went way up to like 81F and thats from 78F the other problem is the amount of water evaporated each day is almost 15 litres my walls are wet because of this. this is a 90 gallon tank i have a heater that now resides in the bottom of the sump and remains unplugged i have a fan over the top of the sump but still the temperature goes as high as 79F this fix is only temporary at best as the hot season is still coming any thoughts would be appreciated