Water Change

[Peter Pan]

I need some basic technique on how to do a partial water change. My local
LFS wont give me a straight answer. I have a 75 gal FOWLR tank with 75 lbs
of Live rock and 3" sand bed. When I do a partial water change, I take the
syphon and dig it into the sand bed (careful not to hurt any animals
burried) and syphone out some water, It kicks up some dust and when the
water inside of the tube is merky, when it clears inside of the syphon tube
I move the tube to another location and repeat the process. My question is
this: Is this the right way to do it? If not what is.. ALSO:
I've been told that if you run a sump tank, you can take the water directly
out of that tank when doing the PWC. Please can someone tell me what Im
doing wrong.. my test results are unchanged after my water changes.. and I
need some help..

[Joe V.]

You don't want to disturb the sand bed, as that's what is doing the
biological filteration. In a healthy system, the bottom of the tank will
eventually clean up ... if it doesn't, you may want to adjust your water
circulation or check the chemical balance of the water (maybe too much
nitrates, phosphates, etc)

I've read somewhere that the water should be siphoned the middle layer i.e.,
not too close to the top (as that should be getting oxygen from the surface)
and not too close to the bottom. I've also read that some websites where
the owners don't even change their water! That's the impossible nirvana you
should be aiming for i.e., the perfect balance of livestock and
biological/mechanical filteration.

"Peter Pan" > wrote in message
...
> I need some basic technique on how to do a partial water change. My local
> LFS wont give me a straight answer. I have a 75 gal FOWLR tank with 75 lbs
> of Live rock and 3" sand bed. When I do a partial water change, I take
the
> syphon and dig it into the sand bed (careful not to hurt any animals
> burried) and syphone out some water, It kicks up some dust and when the
> water inside of the tube is merky, when it clears inside of the syphon
tube
> I move the tube to another location and repeat the process. My question
is
> this: Is this the right way to do it? If not what is.. ALSO:
> I've been told that if you run a sump tank, you can take the water
directly
> out of that tank when doing the PWC. Please can someone tell me what Im
> doing wrong.. my test results are unchanged after my water changes.. and
I
> need some help..
>
>

[Pszemol]

"Joe V." > wrote in message ...
> I've read somewhere that the water should be siphoned the middle layer i.e.,
> not too close to the top (as that should be getting oxygen from the surface)
> and not too close to the bottom.

Are you assuming you have a stratification of the water in a reef tank?
How come with such strong water movement? Water mixes very well, there
are no layers with different amounts of oxygen... think about it.

[Joe V.]

Not assuming anything ... you need to take water from somewhere, so may as
well do from the middle. Definitely don't want to disturb the sand bed like
the original post mentioned, do you agree?

"Pszemol" > wrote in message
...
> "Joe V." > wrote in message
...
> > I've read somewhere that the water should be siphoned the middle layer
i.e.,
> > not too close to the top (as that should be getting oxygen from the
surface)
> > and not too close to the bottom.
>
> Are you assuming you have a stratification of the water in a reef tank?
> How come with such strong water movement? Water mixes very well, there
> are no layers with different amounts of oxygen... think about it.

[Pszemol]

"Joe V." > wrote in message ...
> Not assuming anything ... you need to take water from somewhere, so may as
> well do from the middle. Definitely don't want to disturb the sand bed like
> the original post mentioned, do you agree?

Yes, I agree about DSB, but the thing about water layers was just boooooogus.
Water mixes in a fish tank way too much to expect any static layers in it.
It is not a lake :-)

[CheezWiz]

Pulling from the top is good too since that can develop a lot of DOC scum if
there is no overflow... But you gotta mix the top water up first....

Personally, I go around the tank with a turkey baster to kick detritus up,
then siphon around the rocks to get crab poo and such stuff that will not
stay suspended long enough...

CW
"Pszemol" > wrote in message
...
> "Joe V." > wrote in message
> ...
>> Not assuming anything ... you need to take water from somewhere, so may
>> as
>> well do from the middle. Definitely don't want to disturb the sand bed
>> like
>> the original post mentioned, do you agree?
>
> Yes, I agree about DSB, but the thing about water layers was just
> boooooogus.
> Water mixes in a fish tank way too much to expect any static layers in it.
> It is not a lake :-)