dc wrote:
wrote in news:1158917843.952443.295670
@i3g2000cwc.googlegroups.com:

problems in keeping the bottom of the tank clean, like what you see in
Aquariam stores. I use a syphon pipe but I do not fine this really
works very well and I have recently heard that it is possible to
purchase a mechanical vacum but as yet have no luck. Would be very
grateful if members could advise me. Regards to you all. John

How are you using the gravel vacuum siphon? In my opinion they are the only
decent way to keep the gravel bed clean. Push it all the way to the bottom
of the gravel base to remove the most waste. If the siphon is removing
water too quickly for you to clean the entire bottom, kink the hose as you
move from spot to spot.

Mechanical strainer vacuums are available, but 99% of them are just
gimmicky junk that break easily, don't last long, and end up returning a
cloud of very fine sediment back into the tank anyway. The only one I've
seen that works half-well is made by Eheim, but its price tag is usually in
the area of $99.

The typical siphon vacuum you already have also removes old water which
contains dissolved pollutants a mechanical strainer will not.

As dc stated, it takes a little getting used the vacuum by lifting the
vacuum as go thru the gravel. If you have a fine sand (which I do under
a layer of gravel in some of my planted tanks), I am very careful how
deep I push the vacuum into the substrate.

As for mechanical vacuums, there is a device that I have been using for
about a year which is far superior to the Eheim vacuum. This device
(The Aquarium Cleaning Machine) can both drain the water or after
enough water is changed, you can re-filter the water thru a micron
filter. This unit is powered too.
Here is a link to this machine:
http://americanaquariumproducts.com/...ngMachine.html

Carl