I have sold the 1/5 hp chiller. If you are looking for a chiller for a 125 you might want to consider a 1/4 or 1/3 hp chiller. I ran the 1/5 on a 110 gallon tank with 2 4foot coral life bulbs and 2 4 foot atentic bulbs. I had no MH. It kept up but was a struggle especially during the summer months.