Newbie Questions about Fry

I have got fry from my l144 bristlenose about 2 weeks ago in a 120 litre tank. How much water should I be changing and how often? I currently change around 25 litres every 3 days, mainly to remove the parents poo. Is that ok for now, and ishould I ncrease the changes as the fry get bigger.I have lost 3 fry in the last 2 days. Some fry look paler than others, and the bigger/stronger fry are in the flow of the filter, and seam to eat the glass, instead of eating courgette etc. Should I be feeding them wafers at this point?

When the fry are small i recommend daily water changes of about 10% as they get bigger and stronger you can dial that back.

Dont stress about loosing one or two. There is always a percentage that wont make it, I run on about 10%, bit higher with albinos. Its called natural selection, survival of the fittest