The person has obviously put a lot of time into this and it is a very helpful tool, great job.
But like anything else of this nature, which tries to offer a remote sight unseen analysis, this is to be used as a reference only. If you keep up with the water quality you can most likely keep more than is recommended.
One thing I keep seeing being mentioned is the % of filtration. First of all, in my humble opinion, if you can change enough water the filtration % should not really be that big of a deal because you are always replacing your old water with new water anyway; secondary, I want to say that it is my humble opinion that if you only need say "A" amount of bio to convert your ammonia to nitrate yet you have 5 times more than that amount in your filter it is not really going to make your water any better--you are not going to have 5 times more friendly bacteria because they will only multiply in proportion to your bio load. I believe any bio filtration more than that is needed to convert 100% ammonia to nitrate will not add to the "power" of bio-filtration. With chemical filtration there may be some benefit but for bio filtration 300% bio media volume does not make it 3 times better, it is probably just about the same.
I want to mention this because I do not want any new hobbyists to think if they have 500% filtration their tank will be "cleaner" than if it only has 100% filtration so they can do lesser water change and still be fine.