Upgrading to extenal filter worth while?

[Jon]

I am currently running a Fluval 2+ filter in a 16gal (about 70L) tank.
So basically quite a small tank, the filter came with it as part of
the package from the company who makes it.

While my fish (selection of fancy goldfish) seem happy and healthy,
and test kits show the water with ammonia 0, nitrite 0, nitrate around
40. The water itself at times is quite cloudy, a kind of milkly-off
white.

This could be a cycle, but I have had it since August ;-) As the
goldfish do create a lot of waste I am having to clean the filter
about every 1-2 weeks, I am cleaning it in tank water. Also I am
doing weekly water changes, about 25% or 20L worth of water.

So as I see it, the filter is doing biological filtering, but isn't do
a huge amount of it, maybe it is dealing with too much waste problems?
So a solution could be to upgrade to a Fluval 104 external filter.

These seem much better designed for biological filtering. However,
would this be a bit of an overkill in such as small tank? The Fluval
104 is designed for up to 32gal.

Another problem would be, can I fit the tubes into the tank, the lid
of the tank does have 2 holes in the back for cables/tubes, but they
don't seem that big, so does anyone know the size of the tubes for the
Fluval 104 filter?

Thanks!

Jon.

[Gunther]

In article >, jon18
says...
> I am currently running a Fluval 2+ filter in a 16gal (about 70L) tank.
> So basically quite a small tank, the filter came with it as part of
> the package from the company who makes it.

a Fluval-2+ is rated at 105GPH, which is a bit low for a 16G
tank (7 x 16 = 112). And is this one of those that has the
aeration feature? That is, an air intake you can invoke to
insert bubbles into the filter output? Usually those cause
a drastic (40%) reduction in flow rate and thus effectiveness.
Turn it off if so.

In general, you want more than 7 complete cycles of the tank
per hour, so 16*7 = 112GPH is about the smallest filter I'd
consider, and that's for 2 goldfish. Many of us use 10
as the magic number, and would want a 160GPH pump.
(Note that these "rules" assume consistent use of either
US or UK/Imperial gallons.)

>
> While my fish (selection of fancy goldfish)

What does "selection of" mean? More than two? If so,
that's part of the problem. Unless your goldfish are quite small
they require around 10G each, ultimately.

> seem happy and healthy,
> and test kits show the water with ammonia 0, nitrite 0, nitrate around
> 40. The water itself at times is quite cloudy, a kind of milkly-off
> white.

Usually, this milkiness is thought to be free-floating bacteria
(good biobugs) that need a home. Try adding a simple corner filter
(airpump + sponge) for added surface area. More filtration will
help, if it has a bigger bio-media.
>
> This could be a cycle, but I have had it since August ;-) As the
> goldfish do create a lot of waste I am having to clean the filter
> about every 1-2 weeks, I am cleaning it in tank water. Also I am
> doing weekly water changes, about 25% or 20L worth of water.


>
> So as I see it, the filter is doing biological filtering, but isn't do
> a huge amount of it, maybe it is dealing with too much waste problems?
> So a solution could be to upgrade to a Fluval 104 external filter.
>
> These seem much better designed for biological filtering. However,
> would this be a bit of an overkill in such as small tank? The Fluval
> 104 is designed for up to 32gal.

See above: Fluval-104 is about 125GPH(US), so actually a bit small
for you. I'd not use it in anything bigger than a 12G(US) tank with
goldfish.

>
> Another problem would be, can I fit the tubes into the tank, the lid
> of the tank does have 2 holes in the back for cables/tubes, but they
> don't seem that big, so does anyone know the size of the tubes for the
> Fluval 104 filter?
>
> Thanks!
>
> Jon.
>