I'll have to keep this in mind when I get the basement work finished, and the tanks moved/centralized. I'm thinking a central sump for filtration, with another reservoir keep a steady, slow supply of fresh water running through the system. The outflow would run from the central sump, while the fresh water would run into each tank individually. Such an arrangement would provide maximum fresh water to each tank constantly.
The biggest downside to a central system is the spread of disease. You get it in one tank, you get it everywhere. I'm not reprocessing my water, except for the small portion I use for growing algae.
If the disease is due to parasites or bacteria, then yes. If you are considering of buying a UV, you need to allow enough dwell time (time the water passes through UV light) in order for it to work properly. UV's have a recommended GPH flow rate. For example, a 9 watt UV may have recommended flow rating of 150 GPH, therefore, if you should not connect it to a filter or powerhead that has a flow rating of 200 GPH or more.
With a trickle through system, a low power UV system would work fine, but I'm not sure how you would adequately purify the water. The flows in this system are in the order of a gallon per hour for a multi-tank setup.
Woundn't the UV sterilizers purify the water? I agree that 1 gallon an hour is too slow. I have seen multi-linked tank set up with a waterfall effect with one tank above the other and so on and the water falls from higher to lower and then sent back to the top. Would this work?
The only problem with a water fall setup (from one tank to another) is that the lowest tank would probably have the highest concentration of metals, nitrates, etc.
UV just sterilizes, and anything it kills ends up in the water. Plants only clean up certain things, so the rest build up. In order for plants to be effective they must be removed and disposed of periodically. It would also take a huge amount of plants. It is far more economical to dispose of the water.
Disease and/or parasites can be prevented from entering the system with quarantine tanks. A UV sterilizer on one or mor QT tanks wouldn't be difficult to manage, and would only need to be used when new stock is a consideration. I'm thinking of using the centralized system for breeding and growout of existing, healthy stock.
I have seen several, Central Sump Filtration System.
And they work very well.
If , as ToddnBecka stated. You quarantine any new stock, before introducing it to the system.
And you do not over crowd your tanks.
If you have the space, Rubber Maid makes a 120gal or so, tub.
Used to water live stock. If you are lucky enough to live in a Farming area.
This will increase the water volume of any system.
Put your waste water overflow in this unit, connected to the sewer drain and add fresh water to each tank.
This is a rough Idea, of how this System works.
I have 2 friends that uses different versions of this system.
Along with a On-Demand Hot Water Heater, to heat each tank through tubing.
One has a little over 2000 gallons of tanks, and the other has 8000 gallons of tanks in there Basement.
And all of these tanks are used for fish.
The Bio-load on a system like this , is alot less if you are keeping Inverts.