[ppp]

From what I've read, I've learnt that males may die from exhaustion from chasing the females if the female to male ratio is too high. Conversely, I've also learnt that females may die if too many males are chasing her if the male to female ratio is too high. Even in a case of a more balanced male-female ratio, the spawning process is rigorous one, and may result in damage and sometimes even death.

Being someone who loves big koi, I have opted to have an all-female pond. At the moment I have 15 female koi, averaging 67cm (just a guesstimate as I haven't measured them in 8 months) in a 100 tonne pond (approx 26,500 US gallons).

One of the main problems with all-female ponds is susceptibility to egg impaction problems. I've read suggestions that fasting during the "fertile" months has the effect of making the egg-laden females re-absorb their eggs into their body to cover their lack of protein.

The twist is this. I understand that a koi is a 4 season fish, but I live in the tropics, and water temperatures are normally between 26 and 30 degrees Celsius all year round. I don't have a chiller, but even if I did, I doubt it would feasibly lower my water temperatures significantly below 23 degrees Celsius. Would fasting be detrimental for fish at these temperatures, given that the koi metabolic rate may still be relatively high at these temperatures? Will they lose weight/bulk? Will a reduced feed suffice or must it necessarily be a total fast? Other than fasting, is there any other way to reduce egg impaction problems?

A secondary question is this - how long does it take for food to pass through the entire gut system of my koi at these water temperatures? I've heard suggestions from 2 hours to 2 days. What is it really?

Sorry for this being a strange topic given that many of you are going through cold winters at the moment!