Temp is so important, i worry yours is to low.
Babies should be sitting on clean and dry bedding which is therefore changed at each feeding.
hari.ca
" . If
HOUSING BABIES
Brooders and Containers
There are as many different and successful baby brooders as there are hand-feeding formulas. Some are homemade wooden boxes with electric elements or lights to keep the babies warm. Others are adapted metal game chick brooders or glass aquariums with custom made heaters to partially cover the top or bottom of the tank. Brooders set up with heating pads often result in cooked babies, thermal injuries or cold babies since precise, constant temperature maintenance is difficult (Stoddard, 1988). Another problem with homemade or adapted brooders is their usual lack of humidity control. Human baby incubators and specific commercial baby bird brooders have more accurate temperature and humidity control but are difficult to obtain or can become expensive when many babies have to be housed.
Brooders for Housing Parrot EggsBrooders should be relatively small as an important part of disease prevention with babies is to keep clutches separate and this is limited with large brooders. They should provide constant, even heat that can be finely adjusted, be well ventilated, easily cleaned and have a water receptacle to add humidity.
One set-up which meets many of these requirements uses small aquariums to contain babies which is then placed a much larger aquarium or plastic pan filled with about three or four inches of heated water. The water is maintained at 40°C (100°F) with a submersible thermostat aquarium heater. Salt should be added to the water to keep down the growth of pseudomonas and other pathogenic bacteria. Evaporated water must be replaced so that the horizontally laid heater remains submerged.
Temperature
The ambient temperature and humidity of baby altricial birds must be regulated. Young, up until they are feathered out, need supplemental heat above room temperature to thrive and even survive. Chilled babies, either because of neglectful parent birds or power failure to the brooder heater, will deteriorate quickly. These chicks may die later even after being warmed up. Nursery room temperature should be kept warm between 78 and 82 degrees fahrenheit.
The brooder temperature for recently hatched chicks can remain at the hatching temperature of 35.0°-36.5°C (96°-98°F) for the first few days. Once the baby is eating more solid food, at about 2-3 days of age, it should be kept at a lower temperature of 33.5°-35.0°C (92°-96°F) depending on the species and its metabolism. From there up to about two weeks of age babies should be in an environmental temperature of 32.0°-33.5°C (90°-92°F) (Table 2). If temperatures are to high the chick may exhibit panting, unrest, hyperactivity and have dry, reddened skin (Clubb and Clubb, 1986). Cold temperatures may result in death, poor gut motility, crop stasis or other digestive disorders, failure to feed or beg, inactivity or shivering (Clubb and Clubb, 1986)."
I defer to those who have raised chicks.
But I think you need to increase temp closer to 90f....