substrate change

[Linda]

Is it possible to change from gravel to a finer substrate in an already
established aquarium? And how would i go about doing this?
Thanx Linda

[Geezer From The Freezer]

Linda wrote:
>
> Is it possible to change from gravel to a finer substrate in an already
> established aquarium? And how would i go about doing this?
> Thanx Linda

Linda, I'm doing it now - taking me a while. I'm changing from
gravel to sand. Taking a handful or so of gravel out each time
I do a water change.

[NetMax]

"Linda" > wrote in message
...
> Is it possible to change from gravel to a finer substrate in an already
> established aquarium? And how would i go about doing this?
> Thanx Linda

Yes, use a large diameter hose and vacuum it out. The rate of water flow
must be high (to pick up the gravel), so you will find that the tank
empties quickly. Consequently, it's better to space it out over several
days.

Anecdote warning:
I've done this at work many times (changing substrate colours or types)
so I've experimented with a few different ways. Removing the fish and
objects, I can vacuum (to the very last granule) a 60g tank in about 30
minutes, and be left with a 60g full of sparking clean water. I used 3
hoses and a styrofoam box. Hose #1 (2" dia), vacuums the gravel into a
temporary box (styrofoam box on a stepstool, lower than tank but higher
than sink being used). Hose #2 (python) drains water from this box
(leaving gravel behind). Hose #3 refills tank. Very important to have
an assistant nearby to turn on/off various hoses as their rates will not
be matched up, but it works. De-chlor, dump new gravel in, add a few
rocks & plants and in another 15 minutes, you can have new fish in there.

NetMax

[Toni]

"NetMax" > wrote in message
.. .
>
> Yes, use a large diameter hose and vacuum it out. The rate of water flow
> must be high (to pick up the gravel), so you will find that the tank
> empties quickly. Consequently, it's better to space it out over several
> days.
>

Isn't there also a concern about losing a percentage of your biobugs when
you remove all the substrate at once?


--
Toni
http://www.cearbhaill.com/aquarium.htm

[Geezer From The Freezer]

Toni wrote:
>
> Isn't there also a concern about losing a percentage of your biobugs when
> you remove all the substrate at once?


There is indeed, you "could" throw the tank back into a cycle.
Thats why I've been removing mine gradually, which I would advise
Linda to do.

[NetMax]

"Toni" > wrote in message
hlink.net...
>
> "NetMax" > wrote in message
> .. .
> >
> > Yes, use a large diameter hose and vacuum it out. The rate of water
flow
> > must be high (to pick up the gravel), so you will find that the tank
> > empties quickly. Consequently, it's better to space it out over
several
> > days.
> >
>
> Isn't there also a concern about losing a percentage of your biobugs
when
> you remove all the substrate at once?
>
>
> --
> Toni

For most aquaria questions, the best answer is "it depends".

My understanding is that, unlike the slow reproducing aerobic nitrifying
bacteria we often talk about (in relation to cycling), the anaerobic
bacteria responsible for breaking down detritus in the substrate
reproduces much more quickly, (or for bacteria, 'typically', in the range
of 20 minutes). If this is true, then the probability of upsetting your
tank's biological balance would depend more on how much of your
nitrifying bacteria called the substrate home. If you are only using one
filter and it's a UGF, then the answer is yes, there _is_ a concern if
all the gravel were removed at once. If you are using external filters,
then there is less of a concern.

Unless you are running your tank at the limits of your external
biological capacity, then my experience has been that the gravel removal
does not cause any noticeable problems. I've never run controlled
experiments as a proof (never felt the need or the concern), so I'm only
going by observation and the application of a bit of theory. As always
ymmv. If you are trying this out, posting various water test results
would be instructional for everyone.

NetMax

[Toni]

"NetMax" > wrote in message
.. .
> Unless you are running your tank at the limits of your external
> biological capacity, then my experience has been that the gravel removal
> does not cause any noticeable problems. I've never run controlled
> experiments as a proof (never felt the need or the concern), so I'm only
> going by observation and the application of a bit of theory. As always
> ymmv. If you are trying this out, posting various water test results
> would be instructional for everyone.
>


I'm not.
Just hadn't seen it mentioned in this thread and thought maybe it should be.


--
Toni
http://www.cearbhaill.com/aquarium.htm