I've never really bought Marineland stuff but this heater had really good reviews, it's for my 30 gallon cichlid tank I took away from my nephew that neglected it, I think it's 30 gallons I will have to do measurements to see but I'm not exactly sure how to do that, my question is how do I do the measurements to find out if it is indeed a 30 gallon and if this heater is decent one, in the store it was 45.00 I got it in Amazon for 22