Originally Posted by Tobyornottobyxd
My water change schedule is 20% every other day. However, I've read that a 100% should be done once a week too, but I hear that the large amount of water change could shock a fish and it could die? Should I incorporate a 100% water change into my schedule or am is it fine the way it is? I am not using a filter, and I have java ferns planted in the tank. 3 gallon tank. Thanks!
The only way a water change will shock the fish is if the temperature is too different. You can use a thermometer to match the water from your tap to the tank water temp and then change the water in the tank right after you add the conditioner to the new water.
You definitely need the 100% water change in your weekly schedule because ammonia builds up in the water and you must physically remove it; you're just diluting it a little otherwise and any amount of ammonia is detrimental to a fish.