Hi there, welcome to BYC!
Sorry your chick is failing to thrive.
If you have or are able to get Poultry Nutri Drench it might be able to help. It is my preferred product. If you cannot get it or until you can make an electrolyte mix and hold the chick in your hand, beak facing the bend in your forefinger to help catch and direct the drip... place a drop just below the nostrils on top of the beak. When it rolls around into the mouth the chicks will usually gobble and swallow. Get a couple drop in every 15-30 minutes until you see improvement. Recipe as follows...
Electrolyte recipe...
1 cup warm water, 2 teaspoons sugar, 1/8 teaspoon each salt AND baking soda. Stir until dissolved. Serve full strength.
If you cannot find (or afford) poultry nutri drench, I have used liquid bird vitamins sold in the pet department (maybe even at Wally) for only a few dollars and worked very well. Some folks use baby vitamins with NO iron, but this is only recommended if you have it on hand ALREADY. If you get either of these... give a direct drop to the beak, as suggested above and then add some into the water (according to directions) and use that until it's gone.
I have not tube fed but if that's something you are up for there are threads on how to do so. If by chance the chick already inhaled water and you hear crackling when breathing, prognosis is poor. It already is look bad, but get on the suggestions above and hopefully your second baby will pull through!