thermostat/coolant

Well the topic says it all.After i did a flush the low coolant light stays on/flashes.I have put water and coolant in and they go bye bye.Coolant/water is not in the oil did a change to make sure of that.It is not leaking for the hoses dont checked and made sure they was tight.Dont see any water from the thermostat house but then again who knows.Is there anything i can do to check this out as i have wasted about 30 bux on coolant this month i just thought it was empty thats all lol.Would some Bars stops leak work or is that a bad idea.Any help world be app.

Scoot