Automated PH adjustment dripper or optic dosing

[Mattock Man]

Hi all,

I am trying to build a really simple system to adjust PH automatically for a coco grow.

Basically the idea is a permanently submerged PH sensor in the tank talks to a rasberry pi or similar which then releases the required amount of (in my case with my water supply it will always be) PH down.

I have a buddy who can handle the coding, what I am really looking for are suggestions as to a dripping mechanism or some type of optic (like for pub spirits) that could be manipulated with a motor or in some way switched on/off by the controller.

Ultimately we would use the same mechanism/optic to dose the nutes into the mix but for now we just want to identify a suitable mechanism for administering the ph adjustment liquid.

Have done loads of google searches but still havent a clue. have read over the rasberry pi threads on here but they seem to be mainly for environment controllers etc. and WAY more complicated than what we want/can handle

just looking for a simple but accurate mechanism/tool for dosing small amounts of liquid that we can automate mechanically with some kind of motor (or failing that gravity)

any suggestions very welcome,

cheers

MM

[Guest]

You know you can buy a ph doser right?

I really need one but havent researched them enough. im in coco using biggish resevoirs and my ph steadily rises over the week, which is a problem cause i work away most the time.

all the best with this!

[Prophet]

A servo will turn a tap very nicely and is easy to code with either Pi or Arduino

[Artificial Emotion]

I've got an automatic pH corrector which can run pH up and pH down into your stock solution to adjust the pH automatically. It can also switch on a relay when the float switch is activated.

It uses an arduino and peristaltic pumps. You can buy pH modules on Amazon or ebay and use the code to activate a peristaltic pump to pump pH up or down.

[Artificial Emotion]

Check out these pH and EC modules. You can use them to sense the pH and EC and power a peristaltic pump or two to run pH up/down into your nutrient tank. The module in the middle optically isolates the circuits to prevent noise from throwing off your values from the mains. I can PM you the site where to get them if you want.

Edited August 18, 2016 by Artificial Emotion

[Badders]

@ Artifical emotion -- Would a solenoid controlled valve work (gravity fed)? Seems a bit less work than a pump, I'm guessing you explored that idea, what was the reasoning for going with the peristlatics?

[Artificial Emotion]

I am not sure but peristaltic pumps deal with small volumes whereas I would fear that the solenoid valve would not be as accurate. It might be okay though for all I know.

Peristaltic pumps are easy to use and cheap so I'd recommend at least trying them.

Edited August 18, 2016 by Artificial Emotion

[Mattock Man]

thanks a million for the info guys Im out of the loop. Nice one AE mate I'd appreciate that PM.

really excited now.

MM

[Mattock Man]

AE does the corrector have its own submergeable ph sensor or does it need one buying separately and plugging in?

can I get a link to the corrector itself u use and any other kit -? what's the value of a relay when the float switch is activated?

to refill the tank with water is it?

cheers again budz

[Artificial Emotion]

I found out they do in fact use those flow valves in some pH correcting systems so yes you could use it. That being said, a peristaltic pump would still be my preferred method. They are reliable, simple to use and they easily pump small amounts of fluid.

Sorry about the photo I posted, it's a bit messy and not very clear. Yes I use a pH probe which came with the system, or I have up until now that I've decided to go with a better pH probe from Bluelab:

The industrial pH probe I had which is in the photo earlier in this thread in the jar is actually not that bad and I would just save your money and use that. There's definitely nothing wrong with it but I let mine dry out so I ended up buying the Bluelab one which is easy to maintain and is reliable. The temperature sensor (ds18b20) is also used and is the grey cable in the photo.

The pH device I've got is actually quite a useful bit of kit and you can program it to allow the res to have a range of values of pH, so it's a bit like hysteresis in a thermostat system which means your plants can uptake a range of nutrients more effectively rather than your pH being fixed at a specific amount.

I've decided to use one of those peristaltic auto top up pumps you can buy on ebay to add a programmed amount of a two part nutrient with two separate pumps every day. I'd monitor the EC myself and just adjust the flow rate per day based on that. Eventually I'll make an EC system using the EC module I posted a picture of earlier in this thread.

Edited August 20, 2016 by Artificial Emotion

[rory2005]

I know I am dragging up an old topic, but would love to make something like this, but cannot find the above ec and ph kit, Anyone able to point me in the right direction please?