# Aquarium Calculations

Calculations are given in the form for keying into a calculator.

### CAPACITY

Measure the internal length, height and breadth in inches:

Length x height x width divided by 1728 = Cubic feet

Cubic feet x 6.23 = Imperial gallons

Imperial gallons x 4.55 = Litres

Imperial gallons x 1.20 = US gallons

Litres x 1000 = cc (cubic centimetres, also called ml, millilitres).

### DOSING

For calculating dose levels of medicine subtract 10% from the total capacity to allow for gravel, rocks and equipment, (unless this has already been done by the manufacturer of the remedy, check the instructions).

HEATING

A useful tip is to allow 10 watts for every gallon of water that needs to be heated in a 2 foot tank, 6 watts for tanks up to 4 feet long and 4 watts for tanks up to 6 feet long. That is 10 watts per 5 litres in a 6ocm tank, 6 watts per 5 litres in a 130cm tank and 4 watts per 5 litres in a 180cm tank.

## Suggested Heating Requirements

Aquarium Size(length/width/depth) Approximate total wattage
Inches cm volume of water
18 x 10 x 10 45 x 25 x 25 5 gallons 25litres 30-60
24 x 12 x 12 60 x 30 x 30 10 gallons 50 litres 75-160
36 x 12 x 15 90 x 30 x 38 20 gallons 100 litres l00-150
48 x 12 x 15 130 x 30 x 38 30 gallons 140 litres 120-180
60 x 18 x 18 150 x 45 x 45 68 gallons 310 litres 150-200
72 x 18 x 18 180 x 45 x 45 80 gallons 370 litres 200-300

'Allowance has been made for normal amounts of gravel, ornaments etc. If the tank is kept in a cool (unheated) room in the house, then the above wattages should be increased by 50%. For an unheated building, double the wattage's and lag the back and sides of the aquarium with polystyrene sheets.

### pH

This is a measure of the acidity or alkalinity of water on a scale of 1 (acid) to 14 (alkaline) with the neutral point half way i.e. pH7.

Most freshwater fish prefer a pH of 7 but will tolerate a range of 6.5 to 7.5.

Marine fish require a pH of 8.2, which tends to fall with time in the saltwater aquarium, adjustment must be made if the value goes below 8.o.

To breed many Tetra species, acid water is essential, use peat in the filter or a water storage tank to give a value of 6.2 to 6.5. Easy to use kits for measuring pH are available from the pet shop.

### WEIGHT

Weight of water in lbs. = Imperial gallon x 10 or US gallons x 8.34 or litres x 2.2.

Weight of water in kilograms is the same value as the litres.

For total weight add on the gravel (about 100lb/cubic feet) glass (5Ib/ sq. feet) and rocks.

### GENERAL CONVERSIONS

1 inch x 2.54 = cm

Centimetres x 0.3937 = inches

1 ounce x 28.35 = grams

Grams x 0.03527 = oz

1 gram/litre x 0.17 = ounces per Imperial gallon

1 ounce per Imperial gallon x 6.6 = grams per litre

°F-32 x 0.556=°C

°C x 1.8 + 32 = °F

1 metre (100cms) = 39 inches (approx.)

1 foot = 30cms (approx.)

1 litre (1000cc) = 1.75 pints (approx.)

5 litres = 1.1 gallons (approx.)

### SALT TREATMENT

0.1% = 1gm per litre = 0.16ozs/gallon (Imp)

0.3% = 3gm per litre = 0.48ozs/gallon (Imp)

1.0% = 10gm per litre = 1.6ozs/gallon (Imp)

3.0% (DIP) = 3ogm per litre = 4.8ozs/gallon (Imp)

1 level teaspoon = 1gram salt (approx.)