How much does feeding amount relate to Platy fish population?

Question

I've a 200L fish tank with Platys breeding in it for a couple of years now. While I started with a reasonably small number, I think there are around 30 breeding sized fish in there now plus all their young ones. Plus there is a snail population in there too. For the last year or so I've been feeding the tank about 2/3rd of a teaspoon of ground up pellets per day (I use an old salt grinder).

If I reduced their food to 1/3rd of a teaspoon a day how much would you expect this to reduce the population size? Would it reduce to about half the population or would the mix of fish sizes result in a different ratio?

I like a low maintenance tank, and I don't think the java sword and pothos plants are able to reduce the nitrate levels fast enough for my liking. Resulting in a requirement of more frequent water changes. The fluidized sand filter I made seems to do a good job of converting ammonia / nitrite to nitrate, as I've not seen either register on my testing kit since I set up the tank. But I've been a bit negligent on the water changes lately and tonight while performing one, I noticed one of the adults had dropsy, probably from the bad water quality.

Answer 1

Feeding your fish less food will most likely not change the number of fry your fish get,you might get more surviving fry due to better water quality.

Feeding less food will most likely make your fish live longer and they might stay reproductive for a longer period,the plants in your tank will get more time to remove nutrients before you need to trim/cut back the plants.

Less food will lower the filter load making your filtration more effective in converting waste products,changes in water quality will be more gradual giving your tank more time to adjust to biological changes.

Most problems in a fish tank is related to over feeding so by feeding less you will reduce the risk of problems in your tank.

Your fish will be more acctive in searching for food so less nutrients will be wasted and this will help maintaining good water quality.