Water Level

[Tanks4myfish]

Is there a rule for the amount of water in a tank? I've always filled my tanks to the rim so that I don't see the water line at the top. If I have a 10 gallon tank, don't I want 10 gallons in a tank?

 

[clutterydrawer]

I don't know that there's a rule as such. I put as much in my tanks as possible - the more fish-space the better, after all! However my water sits about 1" below toe very top of the glass because i need space for the top of the heater, also allowance for water displacement when i put my whole arm in the tank - if it was totally full, my arm would push loads of water out onto the floor, which is never good.

 

[fraservet]

most tanks are designed so that the maximum water level is above the visible level of the glass.

I second that you should leave enough room to put your arm in/to float new fish etc.

also if you don't have a lid and your tank is very full, fish can escape more easily

 

[gadazobe]

If I have a 10 gallon tank, don't I want 10 gallons in a tank

There is never the exact amount of water in a tank as the tank suposedly holds. That is a 10 gallon will never hold exactly 10 gallon, or a 180 litre will never hold 180 litres. You must take into acount the substrate, decoration, plants, heaters and anything else that is in the tank. It's normal to lose 15-20% of the volume.

 

[Tanks4myfish]

Thanks, all! Great answers.

 

[Aquascaper]

I have all my tanks filled to just below the horizontal glass support struts, that way you get maximum water capacity with room for displacement. By having the level just below the support struts the surface of the water can still move freely, any more water and the surface motion is stopped by the struts which can reduce gas exchange due to oily build up, etc.

 

[_]im]

and I have this oily buildup, I filledmy 10 gallon tank to brim before I left for the weekend and now have oily substance. So definately no complete filling, its not worth it.

 

[Joby]

All the tanks I've purchased are Hagen/Fluval ones and they have a sticker fill mark in them which is approximately 1" from the top so I make sure I don't fill them over that level