Whilst looking forwards to the summer holidays… and feeling rather depressed about the cost of energy at the moment (a fairly constant worry for me… something I inherited from my dad I think!!) I hit on the idea that during time away from our tanks there is a real opportunity for energy saving I believe….
I wouldn’t dare do anything with respect to filtration but when it comes to heating and lighting there are opportunities I feed.
Firstly heating - I run my tanks near the bottom of the tolerable temperature ranges for my fish anyway personally but dropping temperature a little for a few weeks would slow the metabolism of the fish, reduce the need for feeding etc during that time and I would assume the filtration would soon grow a few extra bacteria to account for any reduction in filtration effectiveness. Would others agree? It’s likely the savings in energy use would be significant here if I assume my heater is on 50% of the time a 250w heater costs me about £1 a day, with lower household temperatures due to heating not being on etc, lowering tank temperature to create less of a gradient the heater is having to fight against seems to make good sense. If even only a 20% reduction in energy demand is produced, that’s still 20p a day saving.
The real opportunity I think is with lighting. Now I have heavily planted tanks so there is a need for some light. You could probably argue in a non planted tank, you could leave the lights off completely. My personal tactic I think will be to vastly reducing the lighting duration - say to 3 hours - and intensity maybe a little too - maybe to 2/3rds power. I think my lights are something like 25w which I reckon equates to about 7p a day to run 8 hours a day but it’s not just the cost the general eco efficiency point still stands… what I can say is reducing to 3 hours at 2/3rds power would reduce energy use by 75% which feels worth something.
The downsides I can foresee are potential losses to filtration from reduced plant growth, however I know plant growth slows towards the end of a lighting schedule at co2 concentrations in the water are depleted and do not feel instinctively (only) any such losses will be significant. Furthermore, it would be seen as a less natural schedule for the fish but with ambient light levels high in summer again I feel this is probably ok - after all there are shady mornings etc in the wild are there not!”?