Corid will only treat Cocci.
Wazine can be used for roundworms.
Since both are to be used in water, I personally would treat for Cocci first. If you have a heavy infestation of worms, then you may want to consider using Valbazen or Fenbendazole for treatment of worms.
Have you had a fecal float to confirm cocci and/or worms?
Corid dosage for Cocci is 1 1/2 teaspoons Corid powder per gallon or 2 teaspoons of 9.6% Corid liquid per gallon
Give for 5-7 days - make sure this is the ONLY water available during that time period. Mix a fresh batch at least once a day.
After they finish treatment offer some poultry vitamins and probiotics/plain yogurt.
Worming dosage for Valbazen 1/2 ml orally and then repeated in 10 days for each chicken or Fenbendazole (Safeguard, Panacur) at 1/4 ml per pound for 5 days in a row.
For using Wazine follow your label instructions.
Just my thoughts.