Hello ,another Newbie

[natalie123]

just adopted a red tailed black shark with the tank n all accsesories off my brother totly new to all this.
been to the fish shop today to get some more info,going to get some more fish to add tomorrow
one question how many gallons/litres does an 18" tank hold?

 

[Piltdownpaul]

18 inch by what ?

 

[natalie123]

oh its 18x10"
do i need to know how many gallons to how many fish i can have? cheers

 

[Piltdownpaul]

yes sort of but it also depends on the surface area of the water which allows gas exchange between the water and the air above it. The nitrate which collects in the water at the end of the "ammonia-nitrite-nitrate" cycle needs to bubble out with the rest being depleted by water changes regularly.