I finally put together my auto water changer. It is cheap, simple, and accurate. I started by finding a digital timer that can go down to a second. It has two outputs that can be programmed separately and up to 9 times a day. There is also a battery backup in it that lasts for days. You can pick one up at Amazon for under $30.
Next I found two identical submersible pumps and connected 3/8" PEX tubing. 1/4" tubing took too long and larger tubing required a larger hole in the wall than I wanted. At the high point of each line I included a tee and duck bill one way valve to break the syphon. This seams to work very well at low pressure and is all plastic, which will stay maintenance free for a long time. The waste line runs through a hole in the garage wall and into the yard drain. I used graduated 5 gallon buckets to calibrate the pumps.
The saltwater is kept in a 55 gallon barrel in the garage, which is located behind the wall the tank is against. I have the pumps set to replace 1 gallon every day, which takes about 1.5 minutes. My reasoning is that this is as good or better than me changing 15 gallons every 2-3 weeks. More importantly this creates consistency in the level of water quality. This is similar to how a calcium doser works apposed to hand dosing once a week.
I check the tank and barrel levels every day to make sure everything is running correctly. I hope to add a ReefPi to monitor the voltage and shut down the system if one pump stops working. Otherwise I will either add or remove too much water every day until I catch the failure.
The entire system cost about $80. That is far less than the $400 systems I see for sale and arguably more reliable.
Next I found two identical submersible pumps and connected 3/8" PEX tubing. 1/4" tubing took too long and larger tubing required a larger hole in the wall than I wanted. At the high point of each line I included a tee and duck bill one way valve to break the syphon. This seams to work very well at low pressure and is all plastic, which will stay maintenance free for a long time. The waste line runs through a hole in the garage wall and into the yard drain. I used graduated 5 gallon buckets to calibrate the pumps.
The saltwater is kept in a 55 gallon barrel in the garage, which is located behind the wall the tank is against. I have the pumps set to replace 1 gallon every day, which takes about 1.5 minutes. My reasoning is that this is as good or better than me changing 15 gallons every 2-3 weeks. More importantly this creates consistency in the level of water quality. This is similar to how a calcium doser works apposed to hand dosing once a week.
I check the tank and barrel levels every day to make sure everything is running correctly. I hope to add a ReefPi to monitor the voltage and shut down the system if one pump stops working. Otherwise I will either add or remove too much water every day until I catch the failure.
The entire system cost about $80. That is far less than the $400 systems I see for sale and arguably more reliable.