I am in the market for a pair of Tunzes for my 90 gallon. They will be ran on the 7095 multi controller. I can get the 6100s for about 290 each. I can get the 6101 for about 310 each. Whats the difference in these two pumps. I thought the 6101 was the updated 6100 but is the 6101 worth 20 dollars more than the 6100. If there the same pump it makes sence to buy the 6100 correct? please help me understand. Thanks