Modern ReefKeeping

What is one of the most onerous tasks in maintaining a saltwater aquarium?  The weekly or monthly water change.  Everyone acknowledges that they are critical to the health of a tank, but no one enjoys doing them.  And lets face it, how often have you missed doing a water change.

Whats the best way to perform a water change?  If you ask 10 different reefers you will probably get 11 different methods of doing a water change.  I suggest that the best way is to not do them at all!  No I don’t mean don’t do water changes, rather to set them up to be done automatically.

I have two large mixed reef tanks, a 125 gallon and a 110 gallon.  I used to do 5 gallon weekly water changes that included carrying buckets up from the basement.  It was literally a pain in the back… I now have 3 herniated discs to prove it.  So I came up with a better way.

This system is run by a dedicated aquarium controller, an AquaController JR by Neptune Systems.  If you already have a controller it can easily be expanded to operate this type of setup.  if not most introductory models can run the system.  I would not run this type of automated system based on mechanical timers as they are not reliable or accurate enough.

I have a fish room in the basement, under the stairs.  In this room I have two 55 gallon drums for water storage.  The one on the left is fresh water and the one on the right is salt.  The plumbing shown in the picture is for transferring water from one drum to the other or to fill gallon jugs or buckets.

From this area I have 3 lines of 1/4″ tubing running to each tank.  The white is for RODI top off.  The blue is to drain the tank.  The red is to supply new SW to the tank.  Each of these tubes runs through a McMaster Carr solenoid valve (www.McMaster.com).  It is p/n 7877K53 and costs about $25 each.  I have used these valves in my tank systems for approximately 5 years with no problems.

The controller is set up to operate everything once a day for each tank.  I am doing small daily water changes rather than larger less frequent ones.  It gives the benefit of not causing a swing in water chemistry due to the new saltwater.  Based on the daily volume I am still doing 20% per month.

The first thing that happens is that the auto top off kicks on for approximately 30 minutes.  My autotop off consists of the RODI system being run directly to a float valve in the sump.  The only way it fills the sump is if the valve turns on and the float is low.  This give some redundant protection.  By running it for 30 minutes I would get a max of 2 gallons of top off.  I only need 1 gallon or less.  If something were to go wrong I would notice it well before the sump overflowed.  You definitely want the system to top off first, so that you are always at a fixed water level before anything else happens.

After that turns off, I open the valve for the drain.  This drain needs to be through a bulkhead to set the low water level.  This water is directed to a floor drain in the fish room.  The valve stays open for 6 minutes which is enough time to drain approximately 1 gallon of tank water.

Finally the controller turns on the supply pump to send new SW to the tank.  This pump can be any number of pumps, you want high head and low flow.  I had a diaphragm metering pump laying around, but a dosing pump would be a great choice as well.  This pump is turned on for 8 minutes and brings the water level back up to its original point.

I do check the salinity in each tank about every two weeks to be sure there are no issues.  So far everything has been running problem free.

So how much does this time and back saver cost?  The controller and 8 controllable outlet strip system cost $200 in a powerbuy.  If you are only doing one tank you need (3) solenoid valves for $75 total.  The tubing cost about $25.  There are miscellaneous fittings, bulkhead and floats if you do not already have them, which I did.  So for about $300 you can set up a system to eliminate the most onerous task in reefkeeping!  That’s less than many people pay for a skimmer!!!

In the pictures you can also see that I have a dual inline TDS meter.  Since my incoming TDS is fairly constant, I am monitoring the RO output and the DI output. If the DI output starts to raise I need to change the resin. If the RO output starts to raise, I need to change the membrane.

If you have any comments or questions regarding this article, I am happy to discuss it.  There is a forum thread that is for this article located here.