About How Many Fish.com

I started How Many Fish.com after the lessons I learned setting up my first 29 gallon tank. I was looking for information on how many fish my aquarium could hold. The one-inch-per-gallon rule is widely panned by serious fish keepers. Of course, exact fish capacity depends on many factors, which serious keepers carefully consider. But I needed to start somewhere. People dedicated to their hobby sometimes have trouble being helpful because their concern to do everything just right makes the hobby seem too complicated to the new person. In my research, I found the surface area rule of thumb. It is simple, but it yields a reasonable, fairly conservative result which made scientific sense to me and seemed unlikely to lead to overstocking. To give it more prominence for the benefit of new keepers, I created this website.

I have since added pages on other topics that may confuse a new fishkeeper

  • Hexagonal tanks, which are have more complex calculations for volume.
  • Aquarium substrate weight, because gravel and sand are packaged by weight, not volume.
  • Cycling, the most important thing a new fish keeper must understand before getting that first fish.

Thanks for visiting. I hope you find it useful. Contact me at the link in the footer with any questions or comments.

If you like simple explanations of confusing things, check our other websites:

!Critical Fishkeeping Equipment

Fish are not set-up-and-forget pets. Consider these items we personally use and recommend that make the setting up and maintenance of an aquarium easier for you and healthier for the fish.

Aqueon Water Changer and Gravel Cleaner
Gravel Cleaner and Water Changer

More Info

Water changes of 10-20% should be done weekly. Vacuum, empty and fill your tank quickly from any faucet with this gadget. No more buckets! Don't forget dechlorinator and a thermometer, too.

Water Parameter Test Kit for Aquarium Fish Tank
Water Test Kit.
Fresh test kits are critical for a new tank. I lost some new fish in a quarantine tank when I missed an ammonia spike due to outdated testing supplies. Liquid kits are far superior to test strips.

MarineLand BioWheel Tank Filter
Bio-Wheel Filters
. The bio-wheel section maintains beneficial bacteria even when filter media is replaced. My Marineland Bio-Wheel has been quiet and trouble-free. TIP: Don't replace the filter media until it is about to fall apart. When clogged, rinse it in water removed from the tank. Over-cleaning can cause an ammonia spike.