Fish tank care? 10 points :D?

You should only remove 10-20% of the water at a time. You should take the 10-20% of water out and then get the same amount of water and before you add the new water you should add the dechlorinator and let sit until the water is at room temperature, but when you are ready to pour the water in pour a little bit and then wait ten minutes and add a little bit more and wait ten minutes. Do this till you get all the new water in. I would recommend that instead of cleaning the gravel and the walls get apple snails. For every five gallons of tank you have get one apple snail.