Newbie, Q about changing water

[Mike]

Hi,

I'm not finding specific information on how and when to change the
water in my tank.

I had mentioned before, I have a 55G tank with 5 comet goldfish (about
1-2" each), a black moor, and a fantail (both about 4"). I also have a
betta (about 2") that I'm going to move to a different tank (I'm
setting it up this weekend). The tank has been set up for about a
month, and the fish have been in there for about 2 weeks. It just
started to get pretty cloudy today, which I understand to be "bacteria
bloom."

So, based on this, when should I start changing the water? I
understand that I should replace about 10-15% of the water at a time,
but how soon should I do this, and how long should I wait before doing
it again?

Also, what's this about vacuuming the gravel? Is there a special tool
for this? I read somewhere online that I can just put crabs in the
tank to keep the gravel clean, but that sounded pretty weird to me.
Any thoughts?

TIA,

Mike

[Len]

There are many siphon tubes available that will clean the gravel as they
remove water.

Mike wrote:

> Hi,
>
> I'm not finding specific information on how and when to change the
> water in my tank.
>
> I had mentioned before, I have a 55G tank with 5 comet goldfish (about
> 1-2" each), a black moor, and a fantail (both about 4"). I also have a
> betta (about 2") that I'm going to move to a different tank (I'm
> setting it up this weekend). The tank has been set up for about a
> month, and the fish have been in there for about 2 weeks. It just
> started to get pretty cloudy today, which I understand to be "bacteria
> bloom."
>
> So, based on this, when should I start changing the water? I
> understand that I should replace about 10-15% of the water at a time,
> but how soon should I do this, and how long should I wait before doing
> it again?
>
> Also, what's this about vacuuming the gravel? Is there a special tool
> for this? I read somewhere online that I can just put crabs in the
> tank to keep the gravel clean, but that sounded pretty weird to me.
> Any thoughts?
>
> TIA,
>
> Mike

[NetMax]

"Mike" > wrote in message
m...
> Hi,
>
> I'm not finding specific information on how and when to change the
> water in my tank.
>
> I had mentioned before, I have a 55G tank with 5 comet goldfish (about
> 1-2" each), a black moor, and a fantail (both about 4"). I also have a
> betta (about 2") that I'm going to move to a different tank (I'm
> setting it up this weekend). The tank has been set up for about a
> month, and the fish have been in there for about 2 weeks. It just
> started to get pretty cloudy today, which I understand to be "bacteria
> bloom."
>
> So, based on this, when should I start changing the water? I
> understand that I should replace about 10-15% of the water at a time,
> but how soon should I do this, and how long should I wait before doing
> it again?

Assuming your tank is cycled (NH3/4=0 NO2=0), not planted, you have
sufficient filtration, and your filter cleaning routine is sound (not
overly cleaning, redundant media etc), then your water change rate can be
arranged to keep the NO3 levels at a set point. For example, if you want
your NO3 to be under 40ppm, then measure your NO3 and then do a 20% water
change. The following week, measure your NO3 again just before doing
your water change. With a few measurements and varying your water
changes (quantity and frequency) you will find the routine needed to
match the rate which causes your NO3 to not exceed 40ppm.

If your tank is not cycled, then water change at the frequency which
keeps your NH3 and NO2 at safe levels.

If your tank is insufficiently filtered or improperly serviced, you
initial problem will still be NH3/NO2 or bacterial blooms.

If your tank is planted, using NO3 as your criteria may not be possible
as the plants will begin removing some of the NO3 from the water, but
will not be removing other dissolved undesirable compounds from the
water. When this happens, (NO3 is consistantly zero), then changing 10%
a week is a guideline often used.

Unless you have poisonous levels to dilute, it's generally a good idea to
minimize the size of your largest water change to 25% of the tank's
volume (less if your source water is different from your tank water), and
increase your change frequency if this is insufficient.

These comments are just my opinion. Some would argue to keep NO3 levels
below 20ppm (and it does vary by fish species), while others would
recommend completely different methology. It's a recipe for you to
adjust, which should result in relatively stable water conditions for
your fish.

> Also, what's this about vacuuming the gravel? Is there a special tool
> for this? I read somewhere online that I can just put crabs in the
> tank to keep the gravel clean, but that sounded pretty weird to me.
> Any thoughts?

Gravel vacuum (wide rigid pipe connected to a flexible hose draining
water into a pail/drain). Crabs are not usually a good tank-mate for
fish (though exceptions always exist). There is no fish or invertebrate
which will consume the feces which will accumulate in the gravel. Either
anaerobic bacteria will break it down (releasing some undesirable
compounds back into the water column) or it's fertilzer for plants (and
too much is a bad thing), or it's mechanically removed (gravel vacuum).

How much you need to vacuum, how quickly the NO3 builds up, and the
stability of your nitrifying bacteria in consuming NH3 & NO2, are all
directly related to the amount of food you put into the aquarium
(starting the food chain in action). This is why overfeeding kills fish
(not because they ate too much ;~). hth

NetMax

> TIA,
>
> Mike