Aquaponic Water Tests

I must admit that I'm one of those aquapons that used to test the water quality religiously, every week, but have become much more relaxed about it of recent months.

With all the discussion on this forum regarding pH, and the timely reminder from Dr George that things do better if the numbers are closer to optimal, I decided a full water work-up was due.

Results: pH - 7.8,   Ammonia - 0.25,   Nitrites - 0.0,   Nitrates - 20-40.

Hmmm - that's a lot better that I was expecting.   My DWC bed has been overflowing over recent months, due to masses of roots in the outlet pipe (yes - I know, it's basic maintenance...), so I was topping up 50 gallons every couple of days which is about 10% replacement.   I suspect that this directly impacted my water quality.  

To adjust the pH, I dumped a cup of muriatic acid in to the radial flow filter.  Normally I'd put this in the top-up 50 gallon drum, but since I've fixed my overflow/leak issue I don't need to top up. Once the acid has been through the filter, gravel grow bed and DWC bed before it arrives at the fish tank, it should be mixed and dilute enough not to worry the fish.   I'll test again tomorrow and repeat the dose if required.   Why 1 cup?   That's from experience with my system.  YMMV.

Ammonia at 0.25 doesn't concern me at all.  I'd rather it be 0, but in the past I chased that holy grail only to find out that the test liquids were showing 0.25 on pure water, so I'm going to put it down as 'close-enough'.

Nitrites at 0.0.  Perfect.

Nitrates at sub 40.  Wow!  Now that's a surprise.  Every since I cycled this system over 18 months ago, the nitrates have been sky high.  i.e. off the charts.  Too many fish, not enough plants.  Fair enough.   But I added two grow beds, tripling the growing area, and the nitrates didn't really budge.  Finally, after growing a serious jungle of plants, tomatoes and beans mostly, replacing 10% of the water every couple of days, and the cold weather stopping the fish from eating, the nitrates have dropped on to the measurement scale.  I'm very, very, very happy with that.

Will I return to weekly water tests?  Probably not.   I'll get the pH to around 6.8 and then check every couple of weeks.  With the water leak fixed, I don't expect rapid changes in water quality until the fish start eating again. Then I'll have to worry about raising the pH, not lowering it.

Arduino : How I got sucked in to the vortex

In the grand world of Aquaponics there are quite a few things that need to be monitored on a regular basis: pH, ammonia, nitrites, nitrates, water level, flow rates, pump status and on and on the list goes.

That's a lot to keep track of, so what to do?  Bernard Baruch is quoted as saying that "If all you have is a hammer, everything looks like a nail".   In my case, as a career computer programmer and IT guy, that means I should be able to cobble together some electronics, networking gear, programming and the Internet to do some of this for me, right?   Definitely.  So I got out my "hammer" and started pounding.

My first thought was to use an old laptop and plug various sensors in to it and push the data to the web.  Easy and convenient.  Did I do that?  Naaaah!   Too easy!  I have mentality that is best summed up by another quote, this time from Michelangelo: "I am still learning".  I had heard about the Arduino microprocessor and thought that this might be a good 'simple' project to get my feet wet.   It's open source?  Cool - I love me some open source.  Ever since the early days of Red Hat Linux the concept of free, useful stuff that lots of people develop to make better, without having to pay a bunch of money all the time to purchase and upgrade, has been really attractive.  Sure, there's always rough edges, but the price is right.

Before I go too much further I must confess to being cheap.  My boss is nice and says I'm 'frugal'.  My friends are more direct and much closer to the point when they say "You're just cheap!".  It's true, and I'll wear it. Proudly. This is one of the reasons the laptop based system was canned.   It just seemed like overkill and too expensive to waste a perfectly good laptop to keep watch over a couple of temperature sensors.  Yeah - I know that I've got several old laptops sitting in the cupboard that are never going to see productive life again, but if the Arduino is as good as they say, knowing how to build and use one looks like a valuable skill to have.

Being cheap, as previous established, I scoured the internet and ended up at YourDuino.com, bought a Starter Set and got to work.  Here's a big plug for the guys at YourDuino.  They're a small operation, but their products work, and Terry really know his stuff.  Check out his tutorials if you are bumping up against the learning curve brickwall.  Their pricing is right too.

It wasn't long before I had an LCD screen connected and was measuring temperatures.  The little black component on the breadboard in the photo is the LM35 analog temperature sensor.

Well, that's pretty impressive. Not bad for a rookie. Not bad at all.

That particular Arduino board was used in a precise timer application for a relative who didn't want to pay hundreds of dollars for a professional unit and wondered if I could come up with something. That sounded like a pretty simple project.  Count some milliseconds, and turn a relay on and off.  Yup - even a micro-controller beginner like me should be able to work that out.  The programmer in me didn't take long to code up a basic user interface with three buttons and an LCD screen.   It worked.  Sort of.  Until it didn't...

Hey, this stuff is fun.  But there was a niggling issue in the back of my brain.  At $30 a throw, these Arduino boards were still too expensive. If I looked around I could probably buy obsolete laptop computers for that much and save myself the headaches.  Surely there is a cheaper way of doing this.  Ah - there is, but you're going to have to get your soldering iron hot and your hands dirty to do it.  Arduino, being open-source hardware, can be built from electronic parts, cheap parts as it turns out.

Some Googling time later I found this: Perfboard Hackduino Instructable

And that's when I heard the angels sing.

Where does Arduino data go?

arduino.clanteam.com