From the sounds of it, watery poop and the fact you took all seeds out of his diet, I think he was not eating enough. It's not good to remove seeds cold turkey, some birds will starve to death. It's okay to give him one tablespoon of seeds a day. They need protein too, which seeds provide. Millet is not that high in fat, and most seed mixes have wheat grains and canary grass seed as well. the fatty seeds are safflower and sunflower. Remove all sunflower from the diet, besides an occasional treat if you like.
The ideal diet would be something like
25% pellets
25% seeds
45% vegetables( green leafy, orange coloured, variety is better- sprouts)
5% grains ( cooked quinoa, buckwheat)
To provide vegetables for the entire day would be difficult as they should be removed every 3 hours ( 2 if you live in hot humid area ), so u would need to provide 3-4 vegetable meals to fulfil this diet, unless you also dehydrate vegetables which should last all day in the cage under the right conditions ( not too hot and humid ) .
So even if you fulfill a diet like this :
25% seeds
40% pellets
35% vegetables
It's still acceptable imo. Just do the best you can without starving your little one
This is how I manage:
This is what I feed:
Always in cage throughout day:
Small amount of seed at bottom perch. (2 Tablespoons if your bird is a seed junky so it doesn't starve while it converts to the diet- remove sunflower and flax seed too high in fat!)
Roudybush pellets / zupreem natural mixed in for variety
Roudybush pellets in a foraging cup with dehydrated banana,apple, kale, carrot, green pepper, brocolli, peas, red pepper. I use a dehydrator - this is optional but it is really nice having dry veges in her cage all day too if you miss a meal due to real life demands)
Leave the healthy foods higher up in the cage to entice them to play with it, taste it, eat it.
Morning:
The monthly chop I cook then store into zip bags and freeze and unthaw for daily use overnight, then reheat 5-10 sec in microwave. (Be careful of hot spots)
Everything cooked:
Cooked quinoa , buckwheat (1 cup each)
Green beans
Cooked sweet potato
Carrot
Brocolli
Cauliflower
Peas
Corn
Asparagus or boy choy
You can mash this up if your bird prefers it this way, baby tiels usually prefer it mashed abit.
*You can use frozen veges and cook them for 5 minutes too. Be wary of Lima beans or certain beans in frozen packaging, they need to be soaked and cooked for a long time. Green beans are safe and cook fast.
Afternoon:
Raw chop
Kale , brocolli, carrot
Every second day add some fruit, apples ,kiwi, bananas grapes strawberries(whatever's on hand)
Day:
Sprouted seeds
(Tops brand- All in one seed mix)
Organic sunflower seed
A seed mix that can be soaked together 8-12 hours:
All organic: Kamut, spelt, pumpkin, barley, buckwheat, millet , sunflower, safflower, alfalfa, brocolli seed.
Optional treat once per week:
Birdie bread
Birds muffin - YouTube
1 cup cornmeal
1 cup almond flour( can substitute for whole wheat flour/corn meal/ whole oat flour)
1 -2 egg
1 cup shredded veges( carrot , kale, anything your bird won't eat normally)
1/4 cup ground natural pellets (roudybush or zupreem I use)
1 banana ( or 1/2 cup applesauce)
Water (til soft and wet)
Optional bird bread additions:
1/2 cup cooked strawberries/raspberries
1 teaspoon sesame seed / chia seed/ hemp seed
1 teaspoon organic pumpkin seed
2 -3 teaspoons of seed mix if this bird is a fussy seed junkie
Coconut oil is safe for light greasing for birds or use muffin papers.
I cook at low temperature for 30-40 minutes , 300 Fahrenheit, but I watch and check every 5-10 minutes as it can vary per oven.
Once toothpick comes out clean it is cooked! Feel free to portion and freeze in zip lock baggies, airlocked contrainer etc.
I add abit of seeds in my bird muffins then hang them on a skewer in the cage and my birds loveee eating and foraging through them !
Please update us , I hope you made sure he is eating enough
