Disclaimer and Safety Notes

General information only

AquariumCalcs explains common guidelines and does the arithmetic for you. Every tank is different, and species, stocking, water source, equipment and experience all change what is right. A result on this site can be wrong for your tank, so please treat it as a starting point and not as an instruction. Use of this site is at your own risk.

Livestock and animal welfare

Fish, shrimp, snails, corals and plants are living things. Stocking guidance here is a rule of thumb. It cannot see your fish, your filtration or your water quality, and it does not replace research into the adult size, temperament and needs of each species. Cycle a tank before you add fish, quarantine new arrivals, feed lightly, test your water and be ready to act quickly if fish gasp at the surface or show signs of disease. If you are unsure, ask an aquatic veterinarian or an experienced local fishkeeper.

Chemicals, dosing and treatments

Dosing tools only do arithmetic. They do not know your product, and they never replace the label. Always take the dose rate from the manufacturer’s instructions for your specific product, add chemicals gradually and test before adding more. Never use an ammonia product that contains surfactants, detergents or scents, and confirm purity before you use it for fishless cycling. Some treatments, including salt, copper, peroxide and many algae and parasite products, can harm scaleless fish, shrimp, snails, corals and plants, so check tolerance first. Keep chemicals away from children and pets, and do not mix them.

Electricity and equipment

Water and electricity are a dangerous combination. Use a ground fault circuit interrupter (GFCI) outlet for aquarium equipment, make drip loops in cords, keep power strips above the water line, unplug equipment before you put your hands in the tank and use heaters, lights and pumps only as their instructions direct. A heater that is too small or too large for a tank can fail or overheat the water, and the sizing tool gives a general estimate only. If you are not trained, have wiring checked by a qualified electrician.

Glass, weight and floors

A filled aquarium is heavy, and water alone weighs about 8.34 pounds per gallon. The glass thickness tool gives a planning estimate based on common hobbyist rules of thumb, and it is not an engineering calculation. Large, tall, unusual or load-bearing tanks, and any do-it-yourself build, need a real structural calculation from a tank builder or glass supplier. The floor load tool compares the load per square foot with a typical residential allowance, and it cannot see your floor joists. For any large tank, on an upper floor or on an older house, ask a structural engineer or experienced contractor before you fill it.

CO2 and fish safety

Pressurized CO2 injection can harm or kill fish if it is set too high or runs at night without surface agitation. The CO2 tool gives a starting estimate and a formula check, and it does not replace watching your fish. Increase gradually, use a drop checker or other reliable test, and reduce or stop CO2 if fish gasp or hang near the surface. Handle gas cylinders and regulators with care and follow the equipment instructions.

Saltwater and reef

Salinity, alkalinity, calcium and magnesium all affect corals and marine animals, and large swings are dangerous. Reef dosing tools use commonly published homemade-recipe ratios, and your own product’s label may differ. Change parameters gradually and test with reliable kits. A refractometer or calibrated probe is more accurate than a hydrometer or a converter.

Prices, quizzes and links

The cost planner gives a rough range, and real prices vary by region, brand and time. The finders choose from a short list of options based on a few answers. They cannot see your tank and do not recommend any particular brand or product. Links to other websites are provided for convenience, and we are not responsible for their content. To report an error, use the Report an Issue form. AquariumCalcs is independent and not affiliated with any manufacturer, retailer or organization.