Electronics - New revised layout

After a great deal of re-thinking (the shop didn't have the stock so I went with the old plan) I've decided against adding a second section of board at 90 degrees to the first.

My demand fish feeder will have to have it's original layout after all.

But I did manage to buy some 10k trim pots.

When you fry around in a plane, there is a way to make the plane do things like turn to the right, and a way to set the plane so it always turns a bit to the right. This allows you to keep the plane pointed slightly into the side wind so you keep going straight. This is called adjusting the trim.

I think.

I read that somewhere.

I cant fly planes or anything.

I just read about trim.

I think.

Anyway, I also think that's the kind of reason trim pots are called trim pots.

The pot bit is potentiometer (volume knob, variable resistor) and what they do is change the amount of resistance they offer depending on the position they are set at. These ones are set with a screwdriver and are normally used to fine tune or trim something before you close up the case and use the controls designed to be used by hand rather than a screw driver.

The 10k stands for 10,000 ohm.

Ohm is a measurement of resistance.


Wire has a low resistance, air has a high resistance, and people have a resistance somewhere in between. That's why we use wires to carry our electricity, and try to keep some air between the power lines and the people.

So when I set the dial on my trim pot with a screwdriver, my PICAXE chip sees a value based on the amount of resistance. The chip translates that into a number between 0 and 255. And then I write some software that says something like...

if its 0 to 9 then theNumberOfFeedsPerDay is 1

if its 10 to 19 then theNumberOfFeedsPerDay is 2

if its 20 to 29 then theNumberOfFeedsPerDay is 3

etc

This gives the user the option to set up to 25 feeds per day.

So the device can be told that the user wants their fish to be fed, say, twelve times a day. As the user turns the dial, a light flashes out the value with a long flash for 10's and a short flash for units. So 12 would flash..

    Long   short  short

The device knows what the human wants, and the human knows where the device is at.

As for the new layout, it looks like the original planned layout.

The three trim pots are on the left with their LED's behind them.

Next is the mode button to switch between normal operation, setting the number of feeds in a day, setting the size of each feed, and setting how much light will be named as dawn, where the user happens to live.

Dawn will be the reset time each day based on light levels.

The last of the new components will be the power switch seen standing upright in the centre at the front.

Aquaponics - Mould

I hate it when nature takes out the bad day it's having, by taking it out on me, and bringing me grief in the aquaponics system. What have I every done to nature?

Oh yeah...note to self - send "sorry"card to nature re: carbon footprint.

I don't mind so much when things go wrong that are my own fault. Sometimes I take shortcuts in the way I build stuff, so I feel that it's inevitable that it will need some "adjustment" at some stage in it's life.

But mould is a different story.

I mean it's still my fault, but I'd still rather it didn't happen because it's kind of icky.

When I built the new grow house, I didn't bother reinstalling the computer box cooling fan I had hanging from the top, to stir the air within the growhouse.

Opps.

So now I see mould on the PVC strawberry towers.







I have no idea how I'm really meant to spell those two words so this will have to do.

I've decided to spell mould, "mould", because when I made molds I used "mold" already, and I cant really see using "mould" for mold, and "mold" for mould would make that much difference anyway so I'll stick with "mold" for mold, and "mould" for mould.

I wouldn't want to confuse anyone.

It's also growing on the strawberry plants.

And that.

Nature.

Is unacceptable.







When my pH dropped too low, someone who knows stuff, told me they thought my leaves were showing a potassium deficiency. It turns out different minerals are available to the plants in varying degrees depending on how acidic the water is.

Sounds fair.

The solution is, you can adjust your pH by adding shell grit to your grow bed. Shells are made of calcium carbonate, and that raises your pH. The natural process of converting ammonia to nitrate via nitrite cases your system to become acidic over time, so the shell grit acts as a balance. It's convenient as well, because the more acidic your system gets, the more the shell grit gets dissolved. Once the system is no longer too acidic, the shell grit stops dissolving.

The system finds a balance.

In the meantime, as I was waiting for my system to gently come back to a pH of around 7, I added some potassium bicarbonate.

This adds potassium, which was a nice boost for my plants, but it also adjusts pH away from being too acid.

So I bought some Eco-RoseⓇ

It's actually sold as a solution to powdery mildew, and I guess that could be the culprit.


I dont actually know what powdery mildew looks like, and it would only take 5 seconds of my life to search for it, but that would take the mystery out of life.

Either way, the strawberries will enjoy it, so I'll give it a go.




Not just Aquaponics - Mould - 120 things in 20 years

Aquaponics - Fish death

It's horrible when you lose livestock. It's even more horrible when you have no idea why.

I found this guy on the concrete. Not such a good place for a fish.

It doesn't look like it was dragged out by a cat or anything. And, in fact, looks in pretty good condition.

Apart from being dead.






The day before the fish death, I added a small pinch of potassium bicarbonate to my system to see if it was a lack that was causing my baby spinach to yellow.

Food grade potassium bicarbonate is an additive that people growing aquaponically have been using for  ages. It's used as a supplement if there are insufficiencies in the fish feed. It's also considered safe to add to your system in the doses I used.

I find adding anything to my system to be a really scary pastime, and would prefer not to ever add anything. In this case it changed the surface tension of the water slightly, and created bubbles.

The bubbles collected around the pipes and looked a little like the bubbles you see on the surface when fish are distressed.

A little like those bubbles but not quite the same. These were slightly looser and bigger than the ones I saw during my fish from the poison bush.

But similar enough to make me uneasy, especially when the next day I notice that one of my fish is missing.



I still have no idea what the problem was, and I'm told the bubbles are normal when you add potassium bicarbonate.

It's possible that the fish just had some other issue.

All the others look as happy as they always have.

I have no idea what caused it, and given the level of the expertise of the people recommending I add potassium bicarbonate, I doubt it had anything to do with it.

I hate coincidence.

And problems I don't know enough about to solve.








And then there were ten.






.