Calculating Fish

[Pidge]

I'm a newbie to tropical fish and would like some advice.

I have a tank 3ft X 1ft & 1ft 3in tall, 20 galls.

When looking on the site, members talk about volume of water in the tank, when talking about the number of fish they keep. My book says it is the surface area that is important - 30cm of fish to 1cm squared. what is the best way to calculate the correct ratio as I don't want to over stock? If it is volume can someone tell me how to calculate this?

Also, could you make some suggestions to go with the fish I already have? I wanted a couple of fish that are a bit showy, but everything I have looked at is going to get too big or are agressive. According to the surface area calculations I can have another 280cm of fish. Of course this could be wrong If I should be taking the volume into account.

At the moment I have:
3 Molly
3 Zebra Danoi
2 Red Honey Gourami
5 Neon Tetra

Many thanks,
Pidge

 

[Essjay]

The surface area stocking guide is the other way round - it's 1cm fish per 30sq cm surface, so your tank could hold 90cm or 36 inches of fish in total using that rule. If you add another 280cm fish, there'll be no room for them to move, that's another 110 inches of fish in a 20 gallon tank in addition to what's already there!

Also, a lot of books are out of date with modern fishkeeping, most people on TFF prefer the 1 inch of fish per US gallon rule.

 

[rabbut]

The volume rule is 1 inch of adult length fish per US gallon of water. This is an easy rule for beginers to follow, but takes no account of the surface area of the tank. It also makes no account for fish lengths. A one foot common plec will kick out far more waste and use more oxygen than 12 neons of an inch a piece. This same issue is true of the surface area rule...

The surface area rule is, as Essjay says, 1cm of fish per 30cm square of surface area.

Again, as covered, many books are out of date. If the book was printed more than 5 years ago, it is pobibly no use to you from set-up and equipment points of view. Breeding details for some fish may have changed. Sizes and mixings are usualy OK though in older books.

When choosing stocking, look at both "rules" and choose somewhere between for "adverage" sized fish. After that, make considerations for larger or smaller fish.

The Zebora Danios need a bigger group realy, of 5-6 After that, in a 20g, you'd be just about done IMO

All the best
Rabbut

 

[Pidge]

It looks like I need to get a better book.

I do love my Zebrora Danios so if they are happier in a larger group I will take you advice and get 2 or 3 more of them in a few weeks tim e and leave it at that.

Thank you both for your good advice.
pidge