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Automated Water Changing

by Bob Krampetz krampetz@aol.com
First published in The Fish Flash, Greater Portland Aquarium Society
Aquarticles

Some months back, wanting to ease the chore of water changes in my fish room, I visited two GPAS club members who had installed their own automated water changing system. The major feature of theirs is that it did not require drilling tanks. At that time I wrote an article for the GPAS Flash describing their setups.

Since then I've begun installing this "overflow" system in my own fish room. Here are a few pictures, and some details and caveats for building your own. It was simple to build; it works with such ease that I'm sorry I hadn't done this years ago. Even if you aren't ready to build this now, keep this system in mind when you plan any new setup. I can't begin to tell you how much this has simplified and shortened my workload in the fish room.

Though it's called an overflow system, it's really a combination of a siphon and overflow. The key to this is a double loop that goes over the edge of the aquarium. (See photo below).

My system is mostly constructed of ½" PVC pipe. You can use the cheaper ‘class 200', a thinner pipe, for the drains. Pipes feeding water to your tanks will be under some pressure and you should consider "schedule 40", a thicker wall PVC pipe.

Home Depot sells the pipe, elbows and "T"s at very good prices. They even sell some parts in quantity lots. A package of 10 - ½" elbows is $1.29 and 10' of ½" PVC pipe is $.99. Each loop needs 4 elbows, 1 "T", about 24" of pipe and one end cap. Additional elbows, "T"s and pipe will connect it to the runoff.

Double Loop Siphon/Overflow:

Note how the "T" joint opening (left) is below the upper, or permanent siphon loop. This "T" is the exit where the water overflows whenever the water level in the aquarium rises above the level of the "T" opening. Obviously, it will be connected to more piping to carry the water off .

The longer pipe is 8" and the shorter ones 6". This tends to leave the water level about two inches below the top of the tank. That allows you to put that much new water in the tank. The "T" opening, being below the new higher water level, causes the siphon to empty the tank into the second loop with resulting overflow until the "T" opening is again at/below the water level.

A 3 Tank completed setup:

Note the additional "T"s and elbows connecting the loops to the 1" floor drain.

The 6" stem that's in the tank has small holes added with a drill. Most joints are glued to avoid leakage of water and to prevent air stopping the siphon.

I keep one or two joints unglued to allow me to remove and restart the siphon if necessary. There's a thin Teflon tape that's sold with PVC that is used for threaded fittings. I used the tape to make the unglued joints snug and waterproof.

Check the fit of the pipe to the elbows when you buy it as I found a few pipes that were looser than most and these leaked quite a bit when left unglued.

Just as when you siphon your tank and you raise the hose back up to the water level the water outflow slows and stops, water outflow from the "T", being close to the aquarium water level, is slow and you will need to have a slow water inflow feed. This can be done using any of several drip irrigation components.

When I completed plumbing my first three 30 gal tanks on a single stand, I tested it by just adding water with a hose from the sink. It worked so well I was tempted to not bother installing the water feed, but after a few days I did add the water pipe and valve feeding into drip irrigation.

Drip Irrigation & Valve:

Typical drip irrigation ¾"valve with manifold fittings for ½" threaded pipe to ¼" hose.

I don't have the valve connected to a timer yet as I'm still adjusting the water flows among various sized tanks and I still connect/disconnect the water at the sink via a quick connect fitting. But I wanted to show the water manifold that the ¼" hose connects to. The larger manifold has 6 individual valves that vary water flow from 0 to 10 gal per hour. The smaller one is a 4 way with no valves. ¼" valves can be added if there's too much water feed. All parts are in stock at Home Depot. I've decided that the drip emitters aren't needed, as the ¼" valves are sufficient to control the amount of water.

Though I used the black ¼" drip irrigation hose, I found that ordinary air line works just as well.

The other systems I looked at are using the ½" black irrigation hose and drip emitters fitted into them. Water pressure should be low, so some control may be needed. I put a pressure reducer inline which doesn't seem to do much. I just adjust my pressure with the hot & cold faucets. There are many ways you can connect and control the water feed, but drip control seems best.

The one point I want to emphasize, you can add the PVC pipes for the siphon/overflow part, run the water to a floor drain or how ever you want to handle the wastewater. This alone will eliminate the pain of constantly standing, watching, restarting and manipulating a siphon.

Just as I had numerous questions about existing systems, email me with questions. If you'd like to see the system, ask – everyone enjoys to showing off their fish rooms, I'm no exception.