No. It really isn't the best tool. While it may seem to take into consideration things like temp and pH, that calculator cannot account for other things like the keeper's ability, appropriately overstocking certain species tanks (like mbuna cichlids or betta sorority tanks) or vastly understocking others (like a ten gallon with two dwarf puffers), messy behavior of some fish (like plecos, platies, or goldies), and, of course, it cannot include experience from other individuals who have tried similar set ups. For example, I just did a ten gallon set up with fairly decent filtration and input one male betta, an African dwarf frog, and a single platy. That calculator, aside from reminding me that frogs and bettas jump, cleared this stocking, while I personally would not put any of these species together because of feeding issues, because a platy would nip a betta (particularly if it is a male platy), and because the frogs are best in species tanks because they are such slow fish.
The calculator also states that the AquaClear 20 I randomly added would provide over 300% filtration, when in all actuality, its GPH would rate it just suitable for a 10-15 gallon tank.
Best thing to do is post your possible stock on a forum like this one so other members can advise based on their own experiences and knowledge obtained through research over the years.
