How much will my tank cost to run?
I’m thinking about starting up my fishkeeping hobby again. The tank I am interested in is an Oase StyleLine 175, which comes with 2 x LED 16W lights, filter and heater. Please could you tell me how much it would cost to run this tank each month? I’ll be keeping community fish.
STEVE SAAR, VIA EMAIL
NEALE ADVISES:
Working out how much an aquarium will cost to run is difficult to say precisely. Something around £15-20 per month for a tropical aquarium between 150 to
200 l in size is about right, but there will be a good deal of variation. Indeed, with increasing gas and electricity prices, budgeting a bit more than that might well be necessary.
Electricity is sold by the kilowatt-hour (kWh), and you can find the price of this unit of electricity on your bill. As its name suggests, to consume one kilowatt-hour of electricity you would need to run a 1000W appliance for one hour (1 kW being 1000W), or a 500W appliance for two hours, or any other combination of power and time that comes to 1000 when multiplied together. You would need to run one of the 16W lights for 62.5 hours to consume 1 kWh of electricity. The two lights would therefore use that amount of electricity in half the time, i.e. 31.25 hours. Assuming they were on for 10 hours a day, they’d burn through 1 kWh in about three days. Looking at my latest bill, I’m being charged about 23p per kWh, or, in the case of the lights, 23p every three days. If we multiply by ten to get the value for 30 days, we’d find that your lights would cost around £2.30 a month to run, if you’re on a similar rate to me.
You can easily do a similar calculation for your filter, though of course these are running 24 hours a day. Compared with lights and heaters, these are usually very efficient in terms of electricity consumption. Even a large canister filter like an Eheim ‘Classic’ 600, with a turnover of 1000 lph is only rated at 20W. That works out at about 14-15 kWh a month, or about £3 or so per month in terms of cost.
The cost of the heater is more difficult to pin down because it’s not ‘on’ all the time. In a warm house, where the ambient temperature of the room and the desired water temperature are similar, it might only be on for a few hours per day. Conversely, in a colder location it may need to work much harder and would therefore be using a lot more electricity. Heaters are the devices with the highest power consumption in most tropical aquaria, with 100 to 250W heaters being widely used. So, even if you determine it’s only switched on for a few hours per day in total, its power consumption may still be significant. Let’s say you had a 150W heater on for six hours per day, that’s about 27 kWh per month, which would add a little over £6 to your monthly electric bill. Setting the heater to a lower temperature, or insulating the sides and back of the tank, would reduce this cost.
Totting this all up, you’re looking at something like £12-£13 a month running costs, excluding the price of water changes, fish food, etc. Collecting rainwater can be a good way to reduce water bills, and if you deliberately understock the tank, and avoid overfeeding, the need for large water changes can be minimised. Fish food is usually a trivial expense, with good quality flake foods costing pennies a day, but it’s worth remembering all sorts of leftovers from the kitchen make good fish foods. My fish regularly get things like the ends of lettuces, slices of cucumber, cooked peas, even small pinches of hard-boiled egg yolk. Scraps of white fish always go down well, too.
If you budget something like £4 a week for your fish tank, you should be fine. It’s a relatively inexpensive hobby when compared with keeping other pets like cats and dogs, which not only require more expensive food, but also run up much higher costs in terms of pet insurance and vet bills.