Re: multiple tank filtering question

[Bill Wichers <billw at waveform_net>]

>I am looking at setting up a bunch of smaller aquariums (5-20g) for the
>purposes of breeding and raising fancy guppies and german blue rams.  I
>plan on planting all the tanks as I love the sight of planted tanks and
>it gives me a good excuse to do so.  The one problem I don't have a good
>solution for yet is an economical way to filter them all.  I was
>considering a single wet-dry filter, but have no idea how I would
>properly handle the water return from the sump.

Fun! You can make use of a single, large wet-dry but you'll need to do a 
lot of plumbing to do it right. Some things to think about first though:

1 - a centralized filter has the advantage of allowing you to maintain all 
the tanks at exactly the same temperature, and with the same water 
chemistry. With the chemistry and temperature all the same between all the 
tanks, you can safely switch fish between tanks with no special 
acclimatization procedures. You have one central place to put heaters and 
expensive accessories like UV systems and that one system can serve your 
entire fish room.

2 - a centralized system will spread any disease from one tank to all the 
others just as efficiently as it can spread anything good throughout the 
system. For this reason a UV setup might be a good idea, although putting 
new fish through a quarantine procedure would be better. A centralized 
system also prevents you from maintaining certain tanks at special 
temperatures or chemistries that are different from the rest of the system, 
unless you run the special tanks separately from the central system

>So, do any of the creative people on this list have any ideas on how to
>build an economical _and_ efficient filter solution for a bunch of
>smaller aquariums lined up next to each other?  They will be going on
>some heavy duty shelving in the basement so it will sorta become my tank
>room. :)  For lights I plan on suspending a long light hood over them
>all and leaving the tanks open.

You *can* do it. What you need to do is make sure all your returns can 
handle substantially more flow than the feeds to the individual tanks to 
make sure you never overflow a tank. The best way to do this would be to 
put standpipes in all your tanks since the standpipe will ensure a specific 
water level and will have the lowest possibility of failure. You can also 
use hang-on skimmer/siphon setups, but you need to make sure that they can 
[a] handle all the flow you normally run through the tank, and [b] not 
break siphon when flow stops (many are designed this way, they do it by 
running the siphon from the tank skimmer to a hang-on box, and the hang-on 
box has what is essentially a small stand pipe in it -- there is an example 
on the Krib with pictures).

What you need is for each tank's siphon or standpipe to feed into a large 
PVC "main" that should run along your fish shelf to the central filter, and 
it should gradually slope down to that central filter. Each tank should 
feed into this system using either a T fitting or a Y fitting, depending on 
the angles involved. Y fittings should "point" in the direction the water 
would be flowing. The main just gets set up so that all the tanks can be 
easily connected into it at convenient locations near each tank or group of 
tanks. You probably want at least 1.5" PVC for this, 2" might be better, 
depending on the amount of flow you run through the system. Individual 
tanks can use smaller (and preferably flexible) tubing to feed into the 
main as long as that smaller tubing can handle the maximum flow you would 
ever run through the tank they serve, plus a little extra as a safety margin.

For a return, you need one central pump with sufficient capacity to produce 
your desired amount of circulation through all the tanks. This probably 
means a fairly hefty pump. You most likely don't need much pressure, but a 
lot of flow, so you will want to look for the "high volume" optimized 
pumps, not the "pressure" or "high head" type pumps. This pump needs to 
feed a return that returns water to tanks (which can be smaller than the 
"main" that brings water back to the central filter), and you need a valve 
at each tap along this main that serves a tank. Think about the return as a 
big air-line system with a valve for each tank -- you need to be able to 
balance the water flowing into each tank just as you would the air going to 
each airstone. You could probably rig a gravity feed return that would 
provide approximately equal flow to each tank, but I wouldn't trust a 
system like that.

Since PVC pipe is pretty cheap, you could build a simple system like this 
for maybe $100-200 in pipe and pipe parts (excluding pump+filter), 
depending on the number of valves. Ball valves, BTW, would probably be the 
best choice in a system like this.

It is also possible in some cases to cut slots in sides of tanks and 
position a bunch of tanks next to each other such that the water flows 
between the tanks, something like this:

in ->
       |
       |__|
          |__|    -> out
             |__|

With the water spilling over the cutout in the upper tanks through a 
trought into the lower tanks in series. You'd probably want to use acrylic 
tanks for something like this since it's easier to machine acrylic than 
glass. If you make one looong tank, you can put a bunch of dividers in it 
and pump water in one end, and have it come out a standpipe in the far end, 
flowing through all the dividers and thus tank sections on the way. You're 
looking at some serious DIY time if you start constructing your own 
multi-section breeding tanks though, but you can build them exactly the 
size you want if you go that route.

         -Bill
In Detroit, MI, where are snow mostly melted just to be put back last night 
about 10 times over

>Robert
>
>--
>Robert Chady
>Cadott, WI  where "all" of our snow has almost completely melted. :(


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