The energy crisis isn't just in the UK. It is mainly caused by Russia invading the Ukraine and the lack of gas and oil coming out of those countries. Grain is another issue and has gone up significantly because of the war.
In most parts of Australia there is also an energy crisis caused by the war. This is because state governments let private companies control power, water and gas, and they put all the gas and oil on the world market for overseas companies. They didn't bother to keep anything in reserve for their own states. This means they now have to buy oil, coal and gas back in from the open market and the price of it has skyrocketed due to the war. Most places over east have seen their power and gas bills triple since the pandemic started and it's expected to go higher and not be fixed for about 5-7 years.
Currently over east they have rolling blackouts (it's winter here and there is snow in some areas) and people literally can't afford to buy food, fuel or pay bills because many were laid off due to the pandemic, and because pay packets haven't increased in 9 years thanks to the previous federal government. The problem has been made worse by the oil and gas companies refusing to buy in oil and gas from the world market saying it's not profitable for them. So now the state governments are in talks to try and get gas and oil brought back into the country.
In Western Australia, our state governments put some gas and oil on the world market but kept a reserve specifically for the state. So whilst other states have screwed themselves by letting greedy private companies take control of power, water and gas supplies, the WA government kept control of it and only sold what it could spare and the rest remains in the state.
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Plants don't grow or take up nutrients when there is no light. So if you have a blackout, the plants won't be using any ammonia and won't be producing oxygen unless you can provide them with a sufficient light source.
"Wardley's Ammogon" or Zeolite (same stuff) will remove ammonia from water and can be recharged in salt water. If you have lots of power failures, then maybe get some and keep it handy in a box filter. Then put it in the aquarium during power failures and run the box filter from a battery operated air pump. Use rechargeable batteries that can be charged during off peak times when you have power.
Feeding the fish less will reduce ammonia production in the aquarium and if you know there will be a power failure on a particular day, don't feed the fish the day before. Or feed them in the morning on the day before the power failure so the filter has time to remove any ammonia produced over the next 12 hours.
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The best way to save money on heating aquariums is to have all the aquariums in the same room and have the room insulated with the door shut. Have electronic devices like televisions, computers, fridges, in the room and they also help to warm it up. This is the opposite to trying to keep a fish room cool so don't get them confused.
Insulating each aquarium with 1-2 inch thick polystyrene foam sheets can help reduce heat loss. You can use thicker foam if you like (say 2-4 inch thick). You should insulate the base of the tank, along with the back and 2 sides. Have a coverglass on the tank to trap heat inside. Thicker coverglass (4, 5 or 6mm thick) work better than thin glass (2 or 3mm thick). If there is going to be a long power failure, put another piece of foam on the front of the tank and a blanket or foam on top. Basically make the aquarium an esky (cooler for the US people).
have aquariums near inside walls and not next to outside/ external walls. The external walls of buildings can radiate cold into a room and make the aquarium cool down faster. Having aquariums next to internal walls (walls that divide rooms) means the walls won't be radiating cold air onto the back of the tank.
Normal aquarium heaters are fine to use if you only have a few tanks. If you have a lot of tanks, heating an insulated room is often cheaper.
Most tropical fish can live in water that is 18C or above. Many can even live in 14-16C water for a few months. However, these are usually the bottom end of the temperature ranges and it's preferable if the water temperature drops slowly over months, not overnight. But having said that, a lot of people (including myself) have had heaters malfunction (usually after a water change) and woken up to a cold tank. When we warm the water up, most of the fish survive. So if the water temperature does drop to 18-22C, don't panic. The fish will usually be fine.
In the UK and northern USA, most houses are well insulated and the aquarium's water temperature shouldn't drop any faster than the house temperature. In fact it should drop slower because water holds temperature better than air does. So as long as the house temp is above 18C, the tank's water temp should be the same.
Bigger tanks will hold temperature better than smaller tanks so whilst it might seem more expensive to run a bigger tank, it might be safer for the fish in the larger water mass if you have lots of power failures. Whilst people might be downgrading their tanks, a well insulated big tank with lights over the middle, might not cost anymore to run than a smaller uninsulated tank with the same light covering the entire tank. And the temperature of the bigger tank will not drop as quickly as the smaller tank due to the mass.
I used to have my aquarium heaters set on 18C in winter and turned them off when the water went above 20C. The fish were fine and lived in 30C+ during summer and 18C over winter. This winter temperature is fine for most fish but discus won't like it.
