30 litre (7 gallon) BiOrb - how many fish? advice please - Tropical Fish Keeping - Aquarium fish care and resources
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post #1 of 8 Old 09-02-2007, 11:13 AM Thread Starter
30 litre (7 gallon) BiOrb - how many fish? advice please

hi there

i have recently 'inherited' a 30 litre (7 gallon) biOrb and 3 fish from a family member.

Could i add more fish or would it make it too crowded?

Thankyou for any advice in advance. :) :)
lillian is offline  
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post #2 of 8 Old 09-02-2007, 11:48 AM
What kind of fish have you got in there already?

I would say you could have 6-10 white clouds or neon tetras depending on whether its coldwater or tropical? The thing with biorbs is that there isn't a lot of surface area or floor area so it's not very good for bottom dwelers or bettas etc, only really mid-dwelling fih.
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post #3 of 8 Old 09-02-2007, 11:54 AM Thread Starter
hi julie! thanks for the reply.

the tank came with three goldfish with fancy tails. - im orry i have no idea what type they are. Isn't that bad
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post #4 of 8 Old 09-02-2007, 12:00 PM
Regardless of the type of goldfish I'm afraid the best option here is to take them to the lfs to be rehomed. I know it's very sad as I have had to do this with fish before but it's for their own good really. A single goldfish needs about 30g to itself, the three of them together I would say should be in no less than 50g tank, but really should be more. The thing with goldfish is that they do actually get huge! Regardless of type they can grow to about 12"! IMHO they should be kept in ponds rather than tanks. They are also huge waste producers so make a terrible mess of the tank in a short while raising amonia levels which are toxic to the fish.

If I were you, I would return the goldfish to a lfs (most stores will take fish from you. They may not give you anything for them but they might give you some store credit or part exchange) and get 6-10 white cloud mountain minnows if you want to keep the tank cold water, or the same amount of neon tetras if you decide to put a little heater in there.

If you do return the goldfish either replace the fish right away with the minnows or tetras, or feed the tank a tiny pinch of food daily just to keep the tank cycled until you add the toher fish.
Falina is offline  
post #5 of 8 Old 09-02-2007, 12:04 PM Thread Starter
oh my!!!

the fish have lived in the tank for over 3 years.

and now i must get rid of them???

:( :( :( :(

when i went to the fish place for a snail the other day they told me 3 goldfish was ok.

i shall do as you say then. But its going to be very sad .
lillian is offline  
post #6 of 8 Old 09-02-2007, 12:11 PM
Lesson number 1: never listen to a salesperson in a lfs.

It is obviously up to you but I'm sure other members will agree that it's just really too small for the goldfish. Have a look through some of the other posts about keeping goldfish in small aquariums and you will see.

It is very sad I agree :( There is a sort of rule that a lot of fishkeepers use: 1" per gallon rule. It's not a failsafe method and has a few holes in it IMHO but basically it says that you should have 1" of fish (adult size) per gallon. There are certain times where tis can be broken. For example with small tetras or minnows because they are such small waste producers and also because they have a long slim body meaning that they don't add up to an inch squared kinda thing. On the other hand there are some fish that break the rules in the opposite direction such as goldfish or plecs because of the hiugh levels of waste, or particularly deep bodied fish such as angels. Like I said it's not failsafe but it gives you a rough idea of the types/numbers of fish that can go in certain tanks.
Falina is offline  
post #7 of 8 Old 09-02-2007, 12:13 PM Thread Starter
thankyou Julie for your soun advice. i appreciate it.
lillian is offline  
post #8 of 8 Old 09-02-2007, 12:20 PM
You're welcome! That's what we're here for.
Falina is offline  

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