Build a ph doser/controller - under $100 - tutorial

[mountainman]

Ok, so what's a huge issue that we're always dealing with in hydro? Ph of course! Personally, I hate having to deal with it multiple times a day, but I can't afford to spend $1500 on a professional doser system. The following system is only an acid doser, however with some tinkering you could likely make it both acid and base capable, however I will not cover that. Making it function as an acid doser is a simple process that will be extremely easy for anyone.

Items needed:
1. Milwaukee SMS122 continous ph monitor/controller - $83 - You can get these off ebay, there's tons of them. Just be sure to get the correct model number, as you must have this one to perform the acid dosing. They do have ones that are only monitors, and that's obiously not what you want. Just match up the model number to be sure you're getting the right one.

2. Smallest submersible pump you can find - $10 - I found one at a hardware store for $10 and it's an extremely low flowrate, only 30 gph. Look for adjustable ones too, I should be able to adjust mine lower.

3. Acid Reservoir - $3 - I just bought a juice pitcher for a few bucks. Make sure that it's plastic, so that it will hold up to the acid just fine. Also, it's important to have a way for air to get in through the top, as it will be needed as you pump the acid out.

4. Appropriate tubing - $2 - you'll likely need 10 feet or less, unless you're in an abnormal situation. Bring your new pump with and just find the smallest tubing that your pump is capable of using. I used 1/4" inside diameter. Color makes no difference, as nothing will grow in the acid anyway.

TOTAL COST: $98

Let's get building!

Well, I guess I'd hardly call it building, but bear with me. This should only take you 20 minutes at the most once you have all your supplies. First, calibrate your new ph meter with two points using 7 and 4 ph buffer solutions. The centerpoint will be off most likely, but the slope will probably already be pretty close. The instructions with the monitor are pretty clear on this process.

So, start by hanging your monitor on the wall so you can easily keep an eye on it while it's running. First off, you'll notice what looks like a ac to dc adapter with a plug in it. This actually does not power the monitor, rather it's a switch that the unit controls. Look at the pictures to understand the setup, but basically when the ph rises above your setpoint, it will turn on this outlet. This is the key to the functioning of this system. Plug that in, and then find the ac-dc adapter for the unit. Attach the ph probe and your monitor should be completly setup! Now, we need to set up our dosing system.

The juice pitcher that you had should be filled with acid. I'm not sure yet what the best concentration is, perhaps we can report our findings as we test it out. But basically, the more concentrated it is, the longer it will be maintainance free. Now, plug your submersible pump into the switch that is controlled by the ph meter. Connect your tubing to the pump, and place it in your acid reservoir.

Now this next part may be key to prevent over dosing! I have used a cable tie to attach my acid tube right to my ph probe. It's up the probe housing from the sensor several centimeters, however by injecting the acid near the probe, it will cause pulses off acid instead of pumping large amounts as the ph fluctuates. Feel free to experiment, but just be careful of what could happen and keep a close eye on it until you're confident you can trust it.

So, go ahead and set your setpoint and sit back to watch your meter automatically dose! If you get more acid flow than you would like, choke back your pump or put a c-clamp on the tube to reduce flow.

I welcome input and discussion on this. I've got it setup, but I just finished a rebuild on my hydro system, so I've gotta wait for the sealants to dry before I can fully test it. I hope this helps alot of people! :D

[mountainman]

more pictures

[Stormcooker]

Now that is the coolest thing I have ever seen. Bravo to you!!!!!!!!!!!
THat WILL help A LOT of people.

[mountainman]

Now that is the coolest thing I have ever seen. Bravo to you!!!!!!!!!!!
THat WILL help A LOT of people.

Thanks! Hopefully it helps you too ;-) There is one word of warning that I forgot to put in, depending on your pump, it's difficult to say how well it will hold up to the acid. I imagine it will depend on the pump, but even if the pump has to be replaced every month, no biggy.

[turtle420]

Wow mountainMan...

VERY Nice!!! I like the idea! I vouch for a Sticky... :)

Question: How do you recon the "base" controller could be made?

[mountainman]

Question: How do you recon the "base" controller could be made?

Well, if you're on a really low budget, you could make some modifications with relays, I'd have to think it out more. But, the easiest way would be to just jump up to the SMS125 unit. This has a plug for acid and a plug for base. Only catch is that it's twice the cost. You can find it on ebay also.

As for the sticky, I think it would be quite helpful for alot of people. I can only imagine the man hours that could be saved :D

[Gen]

I'm going to print this out and save a hard copy.

Great idea!

[Garden Knowm]

I'm going to print this out and save a hard copy.

Great idea!



ME TOO

NICE JOB MOUNTAIN!!!!!!!!!!!!!!!!!!!

love

[Gen]

I'm ordering the controller. I want to build one.

[mountainman]

I'm ordering the controller. I want to build one.

Great! Make sure you post your results and the general performance of it :) Be sure to shop around for pumps too, this time of year there's alot of variety available throughout various stores since it's the start of pond season.

[Zandor]

Very nice job, thanks for the FAQ.

Now what about using step-down hoses and taking the drip hose down to 1/4" then you can put a variable drip valve and then regulate it to just that drip. You just need to turn the valve up or down depending on how fast you want the drips?

Just a thought

[mountainman]

I'm ordering the controller. I want to build one.

Did you order the SMS122 or SMS125?

[turtle420]

MountainMan,

You made the FAQs!!!

Congratulations dude! :)

[mountainman]

Now what about using step-down hoses and taking the drip hose down to 1/4" then you can put a variable drip valve and then regulate it to just that drip. You just need to turn the valve up or down depending on how fast you want the drips?

Where can you buy a drip valve? That'd be an interesting thing to try. Better than using a c-clamp :) Also, where would you suggest finding an adapter to choke down the hose? I have trouble finding any hose barbs in Home Depot and similar stores that sell fittings.

[Gen]

The adaptor is in pond supply or try ice maker parts in homedepot. I got the choke down adapter with my pump 130 gph beckett. But the pump takes 1/2 inch hose.

[mountainman]

Hmmm, I'll take a look at that. A choke down adapter did come with my pump too, but it only chokes it down so much :-/ Oh well. The most important thing is that we have something to activate the dosing now!

[mountainman]

Ok, I looked a little for drip valves online, and I was just being dumb! I guess it's a pretty common hydroponic item, eh? Next time I'm down at the hydro store, I'll be buying a couple drip valves.

[Gen]

MM
I'm getting the sms 122. Do you think the 1/2 inch hose would work or is that too big? I could use a barb and put a 1/8 inch hose in the 1/2 inch hose.

[mountainman]

Yeah, it should work, just choke it down (1/8th inch hose will probably work). As Zandor suggested, look at maybe using some drip adapters from a local hydro store. It'd be nice to use a smaller pump, but as long as you put the injection point near the ph probe, it should keep you from over-dosing. This is because the concentration of acid will initially be very high near the ph probe, then making it shut off fairly quickly (this causes the short bursts I spoke about, and is also why a drip adapter would be a good thing).

[Zandor]

Where can you buy a drip valve? That'd be an interesting thing to try. Better than using a c-clamp :) Also, where would you suggest finding an adapter to choke down the hose? I have trouble finding any hose barbs in Home Depot and similar stores that sell fittings.

At Home Depot you can get all the drip valves you want. As for the step down that's easy. At Home depot you can get a foot of each size of hose where one fits tight into the other thus each hose is a step down to the next OD/ID hose. It may take a few of them but you can make one with ease.

[Zandor]

If you need to tighten up the step down hoses try zip ties.

[mountainman]

So, drip valves in irrigation section? Cause home depot here has all their irrigation stuff packed away till winter is over ;-)

[GluteusMaximus]

I remember seeing a step down adapter at the auto parts store. They're made for vacuum hose and usually will reduce down to a tiny tube (very tiny).

Just a thought.

GM

[mountainman]

Just got the drippers for like 50 cents each. Got three different flowrates to play with. Once I get it tested out, I'll write an addition for the FAQ and hopefull Zandor can add it in.

Also, that was a good idea for building homemade reducers, I don't know why I didn't think of that. Works like a charm.

[mountainman]

Well, my system got filled up again monday, and I've been testing out the semi-homemade doser. Overall, good results. I would highly recommend using drippers for the acid, though. Even with a 1/2 gph dripper, the ph changes fairly fast when dosing, although you can also control the ph change rate with the concentration of the acid too.

But, it's been wonderful. Been spending more time watching, less time balancing! Totally worth the $100. I'm sure the plants are happy with it too. The ph has always been staying between 5.9 and 6.0, but gonna turn it just slightly lower.

Gen, get yours yet?

[GluteusMaximus]

I was wondering about the sensitivity of the probe being near the dispenser. Without very sensitive adjustments it would seem that you could easily overdose the resevoire if the current pulled the concentration away from the probe.

As a thought, how about putting the probe inside a cup with the dispenser tube in the cup as well (cup inside resevoire)....that way a small dose would immediately trigger the shut-off. The cup of high ph would then drift into the resevoire at a slower pace without having to dillute the solution.

GM

[mountainman]

You've got the right idea, however everything is working just fine right now, and besides, it's great for the price you pay for it, and if you balance by hand you'll somtimes see swings of .7 of a ph point. Swings of less than .2 every once in a while aren't too bad.

[mountainman]

Ok, so I've gotten everything working great! It takes just a bit of futzing, but really isn't hard at all. It works great and my plants LOVE it!

Anyone else get one yet and test it? I'd love to hear your results.

[Gen]

still waiting for my controller. I will have tons of questions once I get my stuff. Do you have any more pictures of your grow. I would love to make one.

[mountainman]

I can take pictures of whatever you want with my digital camera. Just lemme know, and I'll be more than happy to help you along the way too.

[Gen]

ok, good. keep checking in. I went to milwaukee website. They wouldn't accept my credit card online. I ended up sending them a check to the wrong address. I'm waiting to hear back from them if they get my check at all. I'm stuck.

I just started using co2 to bring down my ph. It's amazing, but I think it helps to stabilize it. I only had to ajust once in two days. I'm not sure what is going on. Interesting. I didn't like putting chemicals or vinegar in with the roots of my plants. Even though I dumped alot of vinegar in the reservoir and it still didn't seem to hurt them. crazy

[mountainman]

Vinegar, eh? Anyone know if that's ok to use? I mean, it's a weak acid, but it seems kinda silly to use that. But, it is cheaper than the acid you buy at the hydro store.

[Gen]

I am totally abandoning vinegar if this experiment works out and I can't think why it shouldn't.

I assume people have been using vinegar for ages to change ph. In dyeing, vinegar is used to help strike the color on a wool fiber. I try to be as organic as possible. I am not comfortable with sulfuric acid and muriatic acid. I used to work with sulfuric acid and it ate holes in a my clothing. I worked with a rubber apron on and thick rubber gloves. Big ones. I was very careful not to splash.

[mountainman]

I use ascorbic acid, which of course is merely vitamin C. Very safe, I dunk my hands in the stuff on occasion when working on my acid reservoir and no problems whatsoever. But sulfuric acid, I would highly discourage anyone from ever using that for hydroponics. Wayyyyy to strong. I had to neutralize a half liter of it at my lab once and it took me something like 7 or 8 pounds of baking soda and when I tested the ph to check my progress, it just at the litmus paper! Maybe I'll start using vinegar after the current stuff is gone to save money, anyone else use vinegar?

[Gen]

I would think ascorbic acid vitamin C is pretty cheap. I got my bottle of vit c in powder form at Trader Joe's. Cheaper than vinegar. I tried ascorbic acid and got particulate matter precipitating out. I was using organic nutes (my own design). Now, I'm using GH lucas formula for hydro and plants are much happier. I might try it again if CO2 does not work. I'm just tired of lugging gallons of vinegar home to make natural CO2.

Now one guy wants to put a guinea pig in with his grow to generate CO2. That's great! I love all this spontaneous ingenuity.

[mountainman]

Gen

How's it been working out for you? I assume you've had it for at least a week or two now. Mine's been great, totally worth the $100.

[Gen]

Just got it yesterday and don't know what to do???? I'll have to read your excellent post again. Yawn. It's late, have to be tomorrow.

I'm using CO2 to adjust my ph now. Before I used vinegar. I like the CO2 much better. Easier to control ph this way.

[mountainman]

Well, you can definitely use it with CO2 if you want too. I'm still just using some GH acid that I'm mixing from powder. Keep me updated on how it works out. I'm eager to hear good reports :)

[Gen]

Well, since I've been busy with stuff, tell me (I'm really lazy about reading directions) do I need a big CO2 tank to use it with the meter. I've got the small tank used to make soda pop. I'ts from the soda club and it says it will make 110 liters of soda. I am exlusively using CO2 and couldn't be happier. It's great and the plants are loving it. Lush, white roots. I really need to look at the meter tomorrow. The only problem is I have two separate containers for hydro. I would probably need two controllers. One for each. I'm still working out the bugs on my grow. Just moved them outside to natural sunlight and they couldn't be happier. I'll probably need to get a bigger container for hydro or connect them.

Thanks for posting this great idea mountain.

[Gen]

yoohoo, mountain where are you?

I'm going to try this. I guess I need to mix up the co2 in water and put it in container like what you did. I'll try it. Neat and very cool idea mountain.

[mountainman]

Couldn't you pump CO2 straight into the res?

[Gen]

I'm not that smart. How would you do it? I plugged the meter and probe in the electrical and the meter won't come on. I might have a bad meter.

[mountainman]

Did you also plug in the ac adapter? There are two things that look like ac adapters ;-) They both need to be plugged in.

[kushman45]

awsome thanks for the tutorial on this I love DIY self ideas many thanks I am definitly building this much appreciated................A+ :thumbsup:

[mountainman]

awsome thanks for the tutorial on this I love DIY self ideas many thanks I am definitly building this much appreciated................A+ :thumbsup:

It's totally worth the money to me. Let us know how it works :cool:

[Gen]

yeah, I plugged the thing in piggy back style.

[mountainman]

You didn't plug the ac adapter into the other thing that looks like an ac adapter, did you? They both need to be plugged in separately.

[Gen]

doh! Yeah, I plugged one into the other. I'll try it your way if you insist!

[mountainman]

lol

Yeah, if you plug one into the other, it'll never work. The one with the outlet on it is what you plug your pump or CO2 control into.

[Gen]

Great mountain it worked. Do you know how long ph solution lasts opened?

[mountainman]

Oh, the buffered solution for calibration? I'm not certain, I just used my own that comes from bottles that lasts forever as far as I know.

[jvanvark]

How could you adapt this for a swimming pool...? I have a salt/chlorine generator and the side effect is that you constantly need to add acid to keep the ph correct...

Seems like you would need to keep the flow very low - as you would want like 1/2 gallon per 5 or 6 hours max to be added...

Lots of people are facing this issue as salt generators are the hot thing for new pools -- much lower maintenance etc -- but this would be one step even better!!!

Great idea...!!!

[mountainman]

Just hookup a bigger pump if you need to :-)

[hazeywonder]

if you dont like the idea of using a pump like that you can use a pump like this and run it right out of the bottle. You can find them for about 60 bucks this one is 75 but its on the money.. nice things about this is that the solution never touches any kind of anything just the inside of the tube.
http://www.automatedaquariums.com/dp_sys.htm they have premade ones with tds controllers too you can get it wired up for 2 pumps if you us an 2 part...

[Gen]

hi mountain. I never did build that automatic ph system. I am using CO2 instead. It's the bomb. No more chemical nutes for me. Thanks for the info.

[hazeywonder]

gen,

do you use the controller with a bottled tank of co2 like for fish to keep your ph down. I have been thinking of this but wonder if the co2 takes the place of the o2 in the water. I run connected dwc with air stones so I get lots of air but I always wondered if it was a problem. I mean they use it for fishes where they have to breath.. anyways how long have you been running this co2 system? and a little bit more tech side what happens to the co2 i know plants dont use it in their roots like they do under their leafs but is it convereted or does it escape as it passes thought the water and exit as co2 gas?
thanks