Just noticed this thread. I set up a water change system using my Apex about 4 weeks ago. It is running really well now. One setback in the beginning which I will go into to save anyone else the cleanup.
Background
I have about 150g of water volume. A 90g display and a 45g deep blue frag both of which are plumbed into a Eshopps RS-200 sump. All equipment and returns are run off a manifold and a Jaebo DC-9000 pump. The tanks are in my office in the basement. Unfortunately I do not have a drain down there and not a lot of room.
Goal
My plan was to exchange 2 gallons a day.
Materials
Apex w/ breakout box
4 float switches
2 horizontal float switches
2 mj600's
1 Avast Marine Diaphragm pump (ATO)
2 Dry Food Vaults used for water storage. 1 RODI and 1 Fresh Salt (
http://www.containerstore.com/shop?productId=10004271&N=&Ntt=pet+food)
1 Home Depot bucket
I drilled the two pet food containers about 20% up and mounted the two horizontal switches. This is to tell when either container is getting low. Both will send an email and text alert to me when open. I also drilled both through the top off the side of the lid. The salt water container has a 1/2'' hose coming out connected to one of the mj600's inside the container. The hose runs to the return chamber of the sump. The RODI has a fitting for the hose from the AM pump with the hose going down to the bottom of the container. The other end is mounted into the return chamber of the sump. RODI is for my ATO.
I have the other MJ600 in the skimmer section of the sump with the 1/2'' hose going to a bulkhead at the top of the HD bucket. I have two float switches in the return area of the sump. One to control the sump level and one as a backup in case the low switch fails. I also have two switches in the bucket one at a little over two gallons and one slightly above it. Bottom one to stop the waste water pump and the top as a safety.
I timed how long it took for the mj600 in the skimmer section to pump two gallons which was a few seconds over two minutes. I programmed the APEX to turn off the ATO 2 minutes before the water change and stay off for 10 minutes. I then programmed the waste water pump and the new salt pump to come on from 10:30pm. The waste pump is then turned off by the APEX at 10:32PM. The New Salt stays on till 10:33PM. The Waste will stop or not start if the low or high float switches in the bucket are open or if the low salt warning switch is open. The new salt turns off when either the low or high switches in the return area of the sump is open. Both start at the same time so the sump doesn't run dry in the return chamber.
This has worked really well except of course the first time it ran without me there
I had the mj600 for the waste plugged into a regular outlet in the EB8 and it failed to turn it off. I had heard of this happening with dosing pumps because of the low power draw but didn't think of it. Filled the bucket and watered the floor. I switched them both to the manual switches (4 or 8) on the EB8 and haven't had an issue since.
Future plans is to code this into my salinity probe to notify me if going out of range and stopping all together if it is out of whack.
Just figured I would share. Not the most fancy but does the job. I can upload pics or my Apex code if anyone wants to see.
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