Eco labs make serveral products that will not harm your fish but will
prevent mosquitoes from hatching. You can find mosquito dunks,
mosquito bits hide a dunks and Liquid Biological Control at
http://www.richdeer3/site/1566246/page/893773
If you have any standing water I would recommend using the bits or
dunks. If you have a few fish they will eat quite a few bugs as a
snack. Good water circulation will also help.