I started an extremely simple ATO. I have most everything I need but I'm waiting for a couple of parts to arrive yet from China. So far I have my water reservoir and the water level sensor done. This is the sensor 1/4-20 2" (4) Nylon screws (Lowes) $1.30 1-1/2" to 3/4" PVC Tee $1.23 3/8" (5 feet) Pex $1.72 3/4" (1 foot) PVC (0.50) est. Float Sensor (BulkReef Supplies) $10.99 ========================================= Total $15.74 The system is a gravity feed 2 gal reservoir with a servo controlled valve. The feed goes to a Kalwasser reactor. Here are the remainder of the parts Bulkhead 1/4 push 3.99 BulkReef US Plastics 3.31 1/4 Tubing 10 feet 2.50 BulkReef 1/4/ push connect 2.99 BulkReef US Plastics 1.28 Water Tank 7.00 Walmart 1/4 RO solinode 10.00 EBay 24VDC Adaptor 5.00 EBay Clamp 0.70 Lowes ================================= Total 32.18 Grand Total $47.92 So for less than $50 you have an ATO, and that is EVERYTHING. Most systems you purchase leave out reservoir, pumps, hose, clamps and such. This could obviously be improved. It could have redundant floats for safety, It could be tied into a PH sensor, but this is a good starting point. It is possible that I will end up needing on / off float sensors depending on the float sensitivity. We shall see. The sensor bracket can easily be modified to accommodate multiple sensors. I'll post again after it is completed and tested. Just thought I would share. (I love DIY)
And here is the housing for the solenoid valve. Things did not go particularly well. I did not correctly seat the tubing into the valve and had a leak which wen unnoticed for about an hour. But after that, it worked fine, but I am not happy with it. The problem the sensitivity of the float means that it flutters the valve. It will cycle on an off several times per minute. You could argue this is a good thing as it will mean the inflow from the Kalkwasser is essentually a drip. But I don't care for it. I think it will contribute to an early failure of the solenoid which is likely not designed to take that kind of duty cycle. The ideal fix would be to put some logic circuit in control of the solenoid such as a control system like reefKeeper or on my case probably an Adurino. Which I would like to do anyway as I could add a PH sensor and perhaps add wave control and such. But that will be another day. For now, I put this system on a timer to run for 10 minutes every 2 hours using the old timer i built for my Kalkwasser unit. That should save the solenoid from constantly going on and off 24/7, and give it plenty of time to deliver water. It is a short term fix until I can build an Adurino control system. So I guess I could not keep things as simple as I hoped. Sigh. If I ever do an Adurino control build, I post it here.
