Servicing a custom acrylic aquarium

[Richie_ELP]

This Sunday I am helping a friend clean out her custom fish tank that was built into the wall of the house she bought. The tank hasn't been touched in a year.

How would I be able to figure out the amount of water this aquarium holds? The tank is acrylic, the end you are meant to look into is a half circle that pops out, the servicing end is similar to a bow-front. It resembles the display tanks you see at public aquariums. I want to make sure I use enough water conditioner. I do not want to be the one responsible for the fish dying.

 

[philfreenode]

Use this to calculate volume by picking the shape of the tank and entering the dimensions. http://reef.diesyst.com/volcalc/volcalc.html

Use enough dechlor to treat the entire tank volume, not how much water you are adding. If its not shaped like any of that, i would just pick the bowfront option and guesstimate.

Now... from your post it kind of sounds like the water hasn't been changed ever. And you don't want to be responsible for killing the fish. If the tank hasn't been taken care of in a year, and all that has happened is top-offs (adding water to replace what evaporated), there is a high concentration of nitrate and dissolved organic compounds in the water. A large water change now will give osmotic shock the fish and cause them to die. Hardly your fault though it would be your friend's lack of care. Buy an API liquid test kit for nitrate and test them, they are probably off the charts. The fish are surely adapted to the filth that they are in and a quick change in their environment, like sudden clean water or a new fish added will cause mass death. That is called old tank syndrome. You and your friend are going to want to start to remove and replace about 10% of the water per day, for a full week. Then perhaps 20% for a day or two, then do your cleaning combined with a 50% water change. Your friend needs to remove and replace 50% of the water as needed after that, to keep nitrates low. The lower the better, shoot for 20 if possible. Your friend might need to be changing water daily for awhile, once they get nitrate down to double digits they only need to be testing and changing 50% of water weekly.