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Calculators

Calculators We have the largest most advanced selection of aquarium calculators you'll find anywhere on the Internet.

These programs allow you to calculate almost anything, from the number of fish you can keep in your tank, to the precise number of water changes you should be making.

Unit conversion calculators Convertors
A massive range of unit conversion calculators for converting pretty much any aquatic units you can think of.
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Electricity cost calculator Electricity cost calculator
How much electricity does your tank use and how much does it cost? Now shows potential savings possible by switching energy supplier.
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Pond liner calculator Pond liner calculator
Use this calculator to work out how much pond liner and underlay you need, and how much it is likely to cost you.
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Calcium cost calculator Calcium cost calculator
How much does your calcium supplement really cost you and would a reactor be a better option?
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Aquarium volume calculator Aquarium volume calculator
Work out how much water is in your aquarium using our extremely popular aquarium volume calculator.
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Stocking density calculator Stocking density calculator
Work out the approximate number of fish you can keep in your aquarium using our suggested stocking guidelines.
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Carbon dioxide calculator Carbon dioxide calculator
This gadget for planted tank experts can estimate CO2 levels based on KH and pH test results.
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Water change calculator Water change calculator
Are you changing enough water? This unique program can tell you how much to change and how often. It's the key to perfect water.
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Nitrite detoxification calculator Nitrite detoxification calculator
Calculate how much salt you need to add to reduce the toxicity of any nitrite present in your water.
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Temperature change calculator Temperature change calculator
Doing a large water change and topping up with unheated water? How much boiling water do you need to add to keep the temperature stable?
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Ammonia toxicity calculator Ammonia toxicity calculator
Work out the proportion of toxic ammonia to ammonium in your water based on the pH and temperature.
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Pearson's square calculator Pearson's square calculator
Get water of any hardness by mixing harder tapwater with your RO in the right quantity using this clever gadget.
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Treatment dose calculator Treatment dose calculator
Enter the treatment details and the size of your tank and we'll work out how much to add, and tell you how much it will cost.
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rH calculator rH calculator
Work out the rH of your reef tank based on the ORP, pH and dissolved oxygen levels.
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Calcification calculator Calcification calculator
Estimate the calcification rate of your corals and other inverts using this handy chemistry gadget.
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Carrying capacity calculator Carrying capacity calculator
Working out the number of fish an aquarium can support is immensely complicated. This program performs some complex calculations to work this out for UG filters.
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Periodic table Periodic table
Expert fishkeepers often need to refer to the Periodic Table of Elements. Here's our nifty computerised version.
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Salt mix calculator Salt mix calculator
Doing a water change on your marine tank? Use this salt mix calculator to work out how much salt to add.
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Substrate calculator Substrate calculator
Work out roughly how much substrate you need for your aquarium.
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Pond volume calculator Pond volume calculator
Work out roughly how much water your pond contains, and how many fish you can keep in it.
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Pump efficiency calculator Pump efficiency calculator
Estimate the electrical efficiency of your pump or filter with our efficiency calculator.
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Calcium dose calculator Calcium dose calculator
A gagdet for advanced reefkeepers which works out how much calcium you need to add to your aquarium using the raw ingredients.
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Light intensity calculator Light intensity calculator
Calculate light intensity on your reeftank and get recommendations on what lighting you need to add to get better coral growth.
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Turnover calculator Turnover calculator
Work out how many times your water is circulated by your filters or water movement system with this turnover calculator.
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Water weight calculator Water weight calculator
Calculates the approximate weight of the water in your aquarium depending on its salinity.
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Carbon dioxide bubble calculator Carbon dioxide bubble calculator
Work out how much carbon dioxide to add to your planted tank based on its volume and KH.
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