Backyard Aquaponics
A place to discuss aquaponics

Yeah, that might kill it, although it should still conduct.

And if you're comparing with not conducting at all, it should be doable. ie anything vrs nothing.

Yep true that BW. Most of my thoughts was on a single probe with capacitance measurements.

A bit of research on the pH & DO front: Atlas-Scientific appear to be selling products aimed at exactly this.

The only draw-back seems to be the price: aroudn £100 for pH and £180 for DO... a lot of that is postage and VAT so it might be a lot cheaper for those in the states.

On the plus side though:



So that's my major concern taken care of...

If only I could find a cheaper (UK) supplier!

Yeah i have been watching their stuff too.

The temp sensors, while not cheap look like an easy solution too.

I forgot to mention that the pressure sensors can also be used as flow meters (and far less likely to gunk up).

the idea is that you put a differential pressure sensor on a tee and rely on the Venturi effect (or is it Bernoulli's principle?) to drop the pressure in the tee when the water is flowing past.

I'm guessing an equal tee is going to be too large and I may need to fabricate something with a much smaller tee off. (Maybe a straight 40mm section with a 4mm hose barb jutting out?). I plan to experiment a little on the outdoor system as I don't have a 40mm flow meter.

Some sort of calibration is certainly going to be required!

Anyone else measuring the flow in their systems?

http://www.seeedstudio.com/depot/liquid-flow-c-25_32/

might be easier...

Bernoulli rings a bell from some wind turbine research in a previous life.

Man, I wish I paid some attention in school.

Any kids reading this...

PAY ATTENTION!!!

And to anyone under 80 reading this ...

PAY ATTENTION!!!

And to anyone over 80...

SELL YOUR HOUSE AND SPEND YOUR KIDS INHERITANCE ON BRORA!!!

Everyone else...

viewtopic.php?f=50&t=12164&hilit=flow

That's what I'm starting with for my indoor system, I have one in the parts box.

I was thinking abou tmeasuring the flow in the outdoor system; in particular for way of doing it that won't get clogged up and won't hinder the flow.

Do you have any experience of the meters you linked to? Do they get clogged up in AP? Or am I worrying unduly?

No i dont have experince with them. Although i would expect less problems with them than say a small T for pressure.

You may have a point... Perhaps electromagnetic is the way forward!

I have spent a reasonable amount of time reading how to make my own I have the wire there, just need to wind it. One day...

Looks like they updated cosm.com to xively.com...i thought the email was a phishing scam at first..then i logged into cosm.com to find things had changed a bit.

https://xively.com/feeds/180525531

Got a basic version of this working today:

1) I picked up a ps3 eye camera for £9 on fleabay. (any UVC compatible camera should work).

2)Followed this guide to install and configure motion

3)Profit.

The web streaming is clunky (1fps) but I configured the time lapse options and it's great!

I've not set it up to be accessible outside my lan yet, but I have got it uploading a time-lapse video to dropbox. I'll try and youtube that when it's more than a few seconds long

This page had all the drop box syncing info...

Bit of follow-up: The 1fps issue was being caused by motion hogging the cpu. It seems it always uses a fair amount of cpu, even if I've told it not do anything.

As such, I've switched to using mjpg-streamer. I followed this guide but there's an instructable here which may be simpler.

A big problem I found was that the PS3 eye camera does not do onboard mjpg compression. So even with mjpg-streamer the CPU was still heavily loaded. As such I swapped web cams to a logitech one from work. Mjpg-streamer works flawlessly, 30fps over the lan.

I've made it available over the internet but it seems to be satuating my upload bandwidth (probably getting 4/5fps).

This morning I took delivery of a new shiny raspberry pi camera module (£20). I've not played with it, but from what I've read it will work with the pi's on-board h.264 encoder (better compression than m-jpeg, and won't use much cpu). So I should get much better quality for my bandwidth (fingers crossed).

Meanwhile the timelapse is still working well, albeit with slightly shoddy quality:



The snails are my favourite part!

Awesome shots mate. Why does the water level fluctuate so much?

I have not even got an email to order my camera