Backyard Aquaponics
A place to discuss aquaponics

Hi all,
Whilst I'm very green with the aquaponics stuff (especially the hydroponics side) I have quite a lot of experience in automation. If anyone is interested in what they can automate or wants help or advise on the subject feel free to post here and I’ll answer as best I can.
Royale

so how are you with siphons, especially auto-siphons!

Wow, first question after 3 minutes and i cant help a bit

Okay here now Royale - if you read the link referred to on the other topic it is being proposed to use solenoid valves as a way of switching water flow to grow beds in sequence so as to minimise the amount of water being circulated around the grow beds at any one time, at present Steve is sussing out what "Smart Relays" (as opposed to a PLC) are avail, sol valves are readily avail from irrigation places in 20 & 25mm sizes and a simple water level sensor from either Jaycar or a couple of wires dangling in grow bed which completes the cct when wet (not with 240vac on the end tho) so any other methods that could be used or improve what is being discussed would be good:
Here's the link again**

Depending on what else you want to do smart relays might be just fine, the problem with them is usually that are not very (if at all) expandable.
The automaton I want to incorporate is topping up of water in the main tanks, automatic weekly backwashing of the filter, temperature control via a basic solar system and heaters, possibly pH, DO and flow metering for alarms and other things as I think of them. If you wanted to do all that using smart relays you would probably have to buy a few.
Ill be looking at using an Allen Bradley SLC 5/05 for my set-up, simply because I have one sitting around, but they retail for >$5K and are vastly more capable than required.
A better suggestion would be an Allen Bradley Pico controller, they start at about $145 with 8 inputs (2 can be analogue) and 4 digital outputs, go to $460 for 12 inputs (2 can be analogue) and 8 outputs and a screen, and most of them can be expanded by up to 12 inputs (2 can be analogue) and 8 outputs. The Pico has a real time clock and is programmed via software that is a free download. Other similar offerings are available from Schnider/Telemecanique and Mitsubishi to name a few.
Sensors will be the next problem. I’m trying to source a number of different sensors at reasonable cost, but it’s proving to be a difficult task. RS Components have some available, but they tend to be pricey, jaycar is another Im looking at.

I have been thinking of doing something similar. I was looking at phidgets:
http://industrialcomponent.com/phidgets/sensors.html

This would provide a relatively low-cost solution, but there are a lot of things they can't do. Also, of course they require programming. Luckily, I am a programmer.

I was considering setting up the automation so that it does what it can in reaction to a change in things such as water level - and then raises an alert by SMS if things go past certain predefined levels (water level, flow rate, temp, etc).

David C.

Hey im a mechanical fitter, do you have to be an electrical genius to utilise this technology?

nah not at all. Most of the stuff required will be action-reaction kind of programming so it is pretty basic. If you can drive a mouse and picture a switch you will be pretty right.
The electrical side of it is a little more involved, and remember that average joe cant legally (or safely) wire 240V, so get a sparky to do that stuff and do all the 24V AC or DC yourself.

My brother in law is a sparky, its amazing what a carton of beer buys you in labour.

Out of interest for those who don’t want to woken up by a failed pump at 2am, it is quite easy and reasonably inexpensive to set up a standby pump system. Cost/benefit will come down to how much you value your ability to leave the a system unattended.
A simple system could consist of a spare pump (~$60-$200 depending what you want) two relays (~$20 each) a flow switch (trying to find a cheap one), and a few buttons and lights. Basic idea is to start your primary pump with a pushbutton until you see flow (indicated by a light), loss of flow would trigger secondary pump (and a warning lamp to tell you next time your near the setup). Some sort of housing for it would be required, but it shouldn’t take too much to set-up. If anyone is interested in looking into it further Ill answer anything I can (and post pics of mine when its eventually done)

Royale, good thinking, my idea would be to cover a power fail as well
(power loss) or (stuffed pump) = zero water flow
zero water flow initiates backup system (battery operated)

just a thought

Mmm... but the time between cycling will that be an issue?

Sorry - should have clarified (continuous flow pump), that's what I thought Royale was referring to

Thanks Ell!
so then not for syphons?

should say flood and drain