DIY Dosing/Auto Top-Off System

[absolut_racer]

Here is an excerpt from my blog on a DIY Dosing/Auto Top-Off System. I have attached a temporary diagram of the system below:

During this holiday season, the stability of our reefs is a genuine concern while we are away on vacation. To prepare for an out-of-town trip, I have slowly automated various functions to reduce the loss of tank inhabitants. One of the final issues that I needed to remedy was the evaporation in my newest 58-gallon tank, which is still cycling. Because my intention is to move the majority of the tank inhabitants from my 8-gallon and 14-gallon BioCube, I did not want to purchase a third Tunze Osmolator. Instead, I wanted to find a cost-effective solution to replacing the evaporated water. This solution may be used for replacing evaporated water or dosing calcium or alkalinity in a reef aquarium.

Parts Needed

• 1 x Tom Aquatics Aqua-Lifter Dosing Pump
• 8′ x Flexible Silicone Tubing
• 1 x Air Control Valve (Plastic Gang Valve)
• 1 x Digital 7-Day Timer
• 1 x Reservoir for Top-Off Water or Dosing Solution

Optional Parts

• 1 x Check Valve
• 2 x Airline Holders

Instructions

• If you are going to use this as a dosing pump, please take note of how much additive you need to add to your system on a daily basis. If you are using this as a top-off pump, please calculate approximately how much water you add on a daily basis to compensate for evaporation.
• The Tom Aquatics Aqua-Lifter Dosing Pump packaging reads that it will pump 3 gallons per hour a maximum distance of 30 inches. It is important to place this system where liquid does not travel beyond this specified length.
• Measure and cut enough tubing to reach the bottom of your top-off or dosing reservoir that will lead into the input of the pump. The input and output of the pump is notated with arrows.
• I chose to secure the end of the tubing inside the reservoir with a holder to make sure that the kalkwasser would be drawn from the bottom. Also, to prevent a siphoning of the reservoir, make sure the outlet nozzle is placed higher that the level of liquid in your reservoir.
• I then measured 6 inches of tubing and inserted this into the output of the pump. To make sure that water would not be siphoned from my sump, I installed a check valve. If you choose not to use a check valve, measure and cut enough tubing to go from the output of the pump to your main display or sump.
• At the end of the tubing connected to the output, install the air control valve. This valve will help control the volume of water entering your system.
• My initial adjustment of the valve was approximately 1 drop per second. To check the rate of the liquid pumped once you have made your adjustments, you can use any measuring device that you usually use for aquarium maintenance. Once my rate was set, I verified how much liquid was pumped in 1 hour into a 400ml beaker.
• Once I found out the volume of liquid pumped in 1 hour, I divided my total volume of daily-evaporated water to find out how long the pump needed to be on.
• Because I am using this as an auto top-off, I choose to schedule the pump to turn on once the main tanks lights turned off. Dosing kalkwasser at night will help prevent pH swings. The digital timer I am using can accept up to 7 individual scheduled times.

So far, this system has been installed in my 58-gallon aquarium with no major issues.

Note: This project and article was inspired by a member of another forum, glennr1978.

[Hamp]

Nice, thanks Sara.

[Zarathustra2]

I wanted to start adding some dosing in my auto top off system I have today but was concerned with the aqualifter pump. It has warnings on its packaging that make it sound like its very suceptable to getting clogged. Did you ever have any problems with your dosing of Kalkwasser? Also, were you using a standard air-pump to keep the kalk mixed and in suspension or did you have some other sort of stirring mechanism?

[absolut_racer]

Zarathustra2,

For this system, the pump showed no signs of clogging when using kalkwasser. I do want to make note that the method that I mix top-off water uses distilled vinegar/acetic acid, kalkwasser/pickling lime, and ro/di water. This creates calcium acetate and prevents the formation of calcium carbonate, the white precipitate that will usually settle on the bottom of a top-off reservoir. For this reason, I have not tried any hardware to mix the solution at this time. Maybe there are other ARC members that may share their experience with this?

Also, for this type of setup, I would definitely recommend periodically checking the gang valve adjustment, as this item would more likely need attention over the pump itself. Although, I only used this for approximately 3 months, I did not experience any clogging of the pump. However, I think that your concern from the manufacturer packaging is justified, and perhaps the pump should be checked periodically and maintained according to manufacturer specifications?