ATO for Multiple tanks

[Redman88]

okay so i have 3 tanks, currently 2 55gallon tanks and a 25 gallon tank. I am working on moving one 55 freshwater to a 125 freshwater, then will be upgrading the 25 freshwater to a 55 till i get another 125. the last 55 saltwater will be upgraded to something 6 foot long but larger then 125. so yes i am looking at doing an 18 foot wall of fish. So onto the question in the title. How should i control the ATO with just one pump and all tanks plumbed into the same RODI container. I know I will need solenoid valves, already have 3 12v ones on hand, and relays. should i go basic electronic or programmed controller, and why.

 

[mr.maroonsalty]

Easily done with old fasion float valves and tees.

 

[Redman88]

and a constantly running pump? no thanks.

 

[RocketEngineer]

12V Solenoids, A float switch (preferably two) in each tank, and a relay to control the 120V of the pump should do the job.

Connect the two float switches for each tank in parallel with the solenoid valve for that pump. That way the normally closed solenoid will open when the float switches are closed. This forms your control loop.

Connect all three "control loops" in parallel onto the terminals of a single relay to control the pump. When any one float switch closes the circuit, the pump comes on.

When one float switch closes that circuit, the other two circuits are open because the float switches are still high enough. Since the valves are normally closed, the valves to those tanks say closed and the water only goes to the low tank.

A little complicated but it should work.

 

[fermentedhiker]

The problem I see is how to deal with a failure. If a solenoid sticks open when any tank calls for water the tank with the bad solenoid would also get some. A secondary float on each tank that would completely disable the pump and send you an alert that it had gone into fail safe shutdown mode could work, but it may be a lot simpler to use separate pumps in a common container, which would confine any failures to one tank instead of the whole setup.

 

[fishgate]

I am not sure I understand the desire to make things overly complex! Just put in three separate pumps in a single reservoir and be done with it. Pumps are cheap.

 

[EnderG60]

Float valve in each tank connected to a single gravity fed source with a solenoid valve on a timer set to be on for 2-5 min an hour works great for me.

 

[Redman88]

ATO for Multiple tanks

I should mention that the top off tank is out side and the hole in the wall is already feeding power out for the pump and the water line in for the top off.

Edit current set up

 

[mr.maroonsalty]

and a constantly running pump? no thanks.

To each their own. It's been done this way for years. This hobby caters to every taste, but I couldn't handle having to deal with all that electronics, or even begin to explain it to someone watching my tank. You believe a solenoid is more dependable than a mechanical float? The only thing more reliable than a simple mechanical float mounted the correct way are peristaltic pumps set for constant action.

 

[ca1ore]

I assume you are either not running a sump, or are running separate ones for each tank? I run three tank with separate sumps off a single ATO reservoir, but just went with three separate pumps (each with redundant float switches). Seems unecessarily complex with multiple floats and solenoids, but to each their own.

 

[Redman88]

Two of the tanks are fresh water and no sump. The one salt water is currently setup on the ato but it doesn't have a sump either.

 

[RocketEngineer]

If the power for the pump and the water return are all that's going through the wall, then my concept should work. The circuit controlling everything would be inside as well as as the manifold for the three valves.

 

[Redman88]

Currently my top off is running this setup.

 

[RocketEngineer]

The solenoid goes between FS2 and the contact. Everything on the 12V side gets duplicated 3 times, one per tank, and get wired in parallel to the contacts on the relay. D1 doesn't need to be duplicated.

 

[Redman88]

Okay hopefully this shows up



Arrows are on-off-on switches. Pies are solenoids. Squares are relays. Circles are float switches. How's it look

 

[Redman88]

If my pictures are not showing up will some one please quote me.

 

[RocketEngineer]

This is what I was thinking:

Each color is its own tank. The big colored circle after FS2 is the solenoid. The black circles are where the wires actually join each other.

Three parallel circuits connected to a single relay.

Keep in mind that I am a MECHANICAL engineer. I make no guarantees.

 

[triggreef]

and a constantly running pump? no thanks.

No. Gravity fed

Edit- disregard

 

[Redman88]

No. Gravity fed

For three tanks all over 120 gallons. No thanks. Please keep on topic.

Thanks Rocket that's good and simple. Mine has more parts. But as a field electronic tech. I like simple robust redundancy. You did help me clarify my thoughts though. I have no degrees just hands on training working on poorly engineered equipment

 

[RocketEngineer]

Experience is the best teacher. The folks that put our payloads together are amazing. They turn our crazy ideas into reality. The degree is nice but its just the start. Actually doing it a dozen times shows you where the book either comes up short or is flat out wrong.

I just realized you may need some diodes in there to make sure two circuits don't interfere with each other. Play with it and see.