This is the cheaper option
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Lol excuse his language (he's hilarious to listen to). Basically the gist of it, he uses a humidifer and attaches a hose to the nozzle and pipes the fog into the tank. He has a splitter because he has 3 tanks. If you do this, you can turn it down to a low power and it should easily keep your tank at a good humidity for a couple of days. Take some time to experiment with the humidity dial and the screen coverage.