Running Costs

Hi all,

Just wondering does anyone know what are the approximate running costs of an aquarium. I hope to set up a fluval 120 which holds 110 litres. It will be a tropical set up so I'll have a heater and filter and lights.

Any ideas would be welcome.

Thanks,

Martin

Hi Martin,

There are several ways you can approximate the running costs of the tank, but that’s all you can do, you will never calculate the exact costs as there are too many variables.
The best way to get close to the actual running costs is to know the total power consumption of all your tank hardware. Then you use your unit cost from your electricity bill.
The unit cost is per kilowatt hour, so 1000w for 1 hour is 1 unit.
You can easily calculate the cost for filters, pumps etc. which are always on. Simply add up all the power ratings on filters, pumps etc., then divide 1000 by that number to get the amount of running time for a unit of electricity.
It gets more complicated when it comes to lights but still straight forward; you just need to use the "On time" to calculate the amount of units used.
Heaters are a pain to calculate, although they have a power rating, you have no real way of determining the actual running time for the heater. Your heaters will never be on all the time once the tank is up to temp.
The difference between ambient temp (room temp) and tank temp plays a big part in how often and for how long your heater is actually on. In an average house, the heaters in your tank will be on from 1 to 2 hours per day.
So for example;
Lights - assuming 2 x 24W T5 - gives 48W, for a 12 hour on time, this gives a power consumption of 0.576kWH (units)per day
Filters 20W, pump 10W giving a total of 30W which is on 24/7 gives a power consumption of 0.720kWH (units)
Heater, assuming 150W with an on time of 2 hours per day gives a total of 0.3kWh (units) per day.

So for this example, you would be looking at a total of 1.596kWh (units) per day.
Assuming your unit cost is 17C (about average) then you are looking at approximately 27C per day to run the tank.
Obviously the more hardware you use, the more the costs will be.
Hope this all makes sense

Cheers,

Bill.

Thanks Bill,

The only reason why I asked is finances are a bit tight and am trying to reduce my bills. I think I can live with 27c approx. per day but I'll look at my filters etc. and calculate it.

Thanks for your help,

Martin

Hi Bill,

My electricity bills have sky rocketed since i got my 550 litre tank and was just trying to work out if my tank is to blame.

I would say the heater would be have to be on for more than two hours to heat 550 litres would it?

I'm using a FX5 (Think this is 50W), a 300W Eheim heater and just a standard air stone. Not sure of the wattage.

The lights are hardly ever on so this wouldn't contribute much to the bill.

Would you have a ball park figure for what this should be costing a day?

Thanks for the help,

Alan.

The temp of the heater is set to 26 degrees as well if that makes a difference?

Hi Alan,

The tank temp makes a bit of a difference but still won’t be huge. The closer to room temperature the tank is, the less on time for a heater, and conversely the more its set above room temperature, the more on time for the heater. You should still not be looking at a huge amount of on time for the heater. There are a few things that play into the heater on time. Obviously room temperature where your tank is a significant factor as this is the primary driver for how fast your tank loses heat. However, once up to temperature initially, the tank will typically lose heat quite slowly, could go into the technical details behind this but trust me, it loses heat slowly. SO really, the heater is only on periodically as the tank temperature drops below the heaters thermostats activation point, then the heater will come on and heat the tank back to 26C and switch off at this point.
I have done a calculation of your running costs based on the following assumptions,
FX5 on 24 hours per day - uses 1.2Kwh (1.2 units of electricity) per day
300W heater, assuming on time of 5 hours (which i doubt but used to give worst case) uses 1.5Kwh per day
Assuming 10W for your air pump (again, worst case, eheim 400 for example is only 5W) would give 0.24Kwh per day.
Ignoring lights as you said they are hardly ever on, this gives you a total of 2.94Kwh per day, so call it 3 units of electricity per day. Assuming a unit cost of 14.5c (based on Airtricity rate) with a vat rate of 13.5%, this gives a daily running cost of 51c for your tank.

Obviously this is based on the assumptions I detailed, but I think if anything, you will find the estimate is higher than the actual case.

Assuming you are billed every 2 months (60 days on average) this would work out to €30.64 per bill.

Hope this helps.

Cheers,

Bill.

Brilliant thanks Bill.

I thought it would be around that.

My wife was pointing the finger of blame at the tank so i can tell her to head off now and leave my tank alone

lol, had the same thing myself until I pointed out that the tanks were only costing €15 per month

Not to sure about approx running costs, what I do know is after I got rid of my 150w metal halide the electricity bill dropped €200 ...