Fasting

[Seanthebusdriver]

I am trying to establish if there are any benefits in fasting my fish for short periods of time, for example for one day per week. I've found lots of people who do but very little information as to why.
 
My aquarium is properly cycled and the water is within the required parameters and all the fish appear to be healthy. I have 13 juvenile Discus and 9 Corydoras that eat everything I give them. I am feeding them frozen beef heart and a porridge (unknown recipe) that my Discus supplier gave me with the fish when I purchased them about 3 months ago. In addition they get frozen blood worm as a treat once a week. I also put a couple of soft catfish pellets in just before lights out, again, this has all gone by the next morning.
 
So, is it a personal preference to fast your fish or is there any science behind it?

 

[NickAu]

 
I am trying to establish if there are any benefits in fasting my fish for short periods of time, for example for one day per week. I've found lots of people who do but very little information as to why.

IMO if you are feeding a good quality pellet like New Life Spectrum, Omega one Xtreme fish food or Dianichi there is no need to fast, The practice of fasting is useful if the food has a lot of fillers.

 

[Ch4rlie]

Fasting fish once or twice a week in fact can be of benefit to the stocking.
 
This helps to encourage the stocking of your tank to forage in the tank for any leftover foods, this helps to keep the tank clean and keeps the fish active, also by fasting you are helping to ensure you are not over feeding the fish. One other benefit is that this purges their bodies and helps to keeps them healthy.
 
I personally feed my stocking once a day and deliberately miss one or two days a week.
 
In fact most stocking, provided they are healthy and well cared for will easily go a week without being fed, just ensure they get fed for 3 consecutive days and doing a large water change before leaving them alone for a week. This is especially useful if you plan to leave for a holiday or suchlike. 
 
I have done this with my own stocking and left them for 10 days in this way and returned without any problems in the tanks at all whatsoever. 

 

[HarpyFishLover]

I miss Wednesdays and Saturdays, and sometimes forget to feed them other times.

 

[Byron]

Good points raised by responders, and Ch4rlie also has some good reasoning.  One must remember that fish will eat if food is present, to the point of overfeeding in the aquarium (something that would rarely if ever occur in the wild), and this has consequences.  First on the fish, the metabolism is significantly affected, and as all this extra nutrition is not needed, this tends to be more detrimental than beneficial.  Then there is the biological system; what goes in to a fish will come out, so if you feed double the necessary food, you are causing double the waste and twice the effect on the system.  This can have consequences too, particularly in tanks that may be well stocked or close to the sustainable level should anything go wrong.  For instance, a power outage overnight will be much more decimating in a tank that has more fish per volume, and is being fed too much, than it would in a more balanced system.
 
Fry need more frequent feedings, but healthy mature fish can use less.  The high quality prepared foods of today are better choices than we had many years back, and keeping fish hungry will mean better overall health.  Missing a day or two a week is probably a good idea; I miss one day a week, and water change day is a good one to miss as fish should never be fed prior to any sort of upheaval or stress, and given time to "calm down" afterward.
 
Byron.

 

[AbbeysDad]

I dunno, my fish seem to be constantly foraging for food. I think this would also be the case in the wild. Plant bits, algae, larva, worms, insects....
Sure, it's not always a feast, but bits throughout the day...everyday. I don't think they fast any day, although there may be days when food is scarce or not available.
So I think you can withold feeding a day or so per week, but if you're feeding high quality food in small amounts, you could feed regularly.