I need to write this for my fish blog

I need to write this for my fish blog, Can you correct? Please tell me if it makes sense?

The different isn't significant enough between a fish tank of 10 to 40 liters. If you want to put your fish in a 40 liter tank you could just as well put him in a 20. It wouldn't make a difference. The difference is noticeable between 80 to 120 liters. So if you have a 80 liter tank and want to get a 100 or 120, that wouldn't be a waste of money. There are some fish that can live only in 100+ liters.

I want to start a sentence like thus. Is it correct?

The only difference significant enough to be mentioned is...