Ducklings cannot yet regulate their body temperature, so a brooder (a heated poultry box) is necessary. Newborn ducks need to be kept at 86°F (30°C) for the first week and at 81°F (27°C) after that.  After 4-6 weeks, ducks can regulate their temperature and no longer need to be kept in a brooder. Brooders can easily be bought online or at a pet store. If your ducklings seem to be panting, turn the brooder temperature down a couple of degrees. Ducks that are 35 days old or older and ducks who are laying eggs need to be kept at 55°F (13°C). Ducks that are clustering together are likely cold, and if they are panting, they are too warm. Watch for this, and adjust the temperature accordingly.  Provide cool water for ducks to swim in if the weather is extremely hot. A small wading pool can work well for this purpose. However, if you don't want them going into your own swimming pool, check out the wikiHow How to Keep Ducks Out of a Pool. Keep the ducks somewhere you can maintain the temperature. Newborn ducklings only require 289 square centimeters (.31 sq ft) each to roam, and this amount increases as they age. Ducks 3 days of age need 1024 sq cm (1.10 sq ft), ducks 1 week old need 2304 sq cm (2.48), and ducks laying eggs need 2500-2809 sq cm (3 sq ft). If the pen has wire floors, floors for ducklings under 3 weeks should be constructed of 1.9 cm (3/4 inch) mesh and 12-gauge welded wire. This should be attached to a frame designed to keep the wire flat and minimize manure accumulation. For ducks over 3 weeks, use 2.5 cm (1 inch) mesh. Vinyl coated wire or smooth galvanized wire is preferred.  The pen should be secure enough so the ducks do not escape. The shelter should protect from raccoons or bobcats, especially if the shelter is outside. Non-wire floors are fine, as long as there aren’t lots of places the ducks can scrap their fragile feet. Ducks are messy birds with liquid excrement, which is why you must sanitize the housing with a non-toxic disinfectant at least 3 times a week. Their housing also needs...

TL;DR in Indonesian:
Pelihara itik yang baru lahir di dalam kandang berpenghangat selama 4-6 minggu. Jagalah temperatur yang optimal untuk itik dewasa. Sediakan kandang yang cukup luas agar itik bisa berjalan di sekitar kandang. Tempatkan itik di kandang dengan perlindungan dan lantai yang baik. Pastikan kebersihan dan ventilasi kandang tetap terjaga. Berikan cahaya pada itik selama 14-17 jam setiap hari. Biarkan induk itik yang sedang bersarang mengerami telur-telurnya.