24hr PH Graph...to see natural ph swing

[Bad Inferno]

OK for those that assume pH is stable have a look at the graph below provided by my pH meter and web data logger. I have run out of CO2 and you can see the natural variation during a day. With "controlled" CO2 the variation is only +/- 0.02 pH....I could not imagine what the pH swing would be for those that stop and start CO2 injection... Just probably shows what fish can tolerate.

The tank is moderately planted... and the KH is 3 degrees. I use CO2 for ph stability, so I don't worry about storage water pH and a side benefit is plant growth. Normally runs at 6.4 pH ~CO2 = 25 ppm

http://img.photobucket.com/albums/v319/rjconway/ph1d-1.png

[Bad Inferno]

Here is a link what the pH generally looks like, when its controlled. Although this was done a couple of months ago. Note this trend is on a different scale so it looks a little noisy. This link shows 6.2 -7.0 ph as apposed to the one above 6.2 - 8.0 ph. You can just see the water change swing for pH, TDS went down and the temp also goes down 1 degree. Cannot see temp as menu is over the trend area

http://img.photobucket.com/albums/v319/rjconway/Homepage.jpg

[mcloughlin2]

Wow great post!

I'll be saving this on my computor for future reference! :D

[Bad Inferno]

Can you see when the lights come on this morning ? 8:30

[Robdog]

Thats really interesting. And in such precise detail. What kind of monitoring system is that?

[Stingray]

I have also trialled my tanks in the past with a ph controller and an empty bottle of co2. My planted tanks both had a consistent swing of around 0.3ph each and every day. It was also interesting to see how black gravel has a ph rising effect. The black gravel raised the ph from 6.7 to 7.8ph within about 3 weeks ! And then it maintained at this level thereafter.

[Davo]

I run my CO2 on a timer so when the lights come on the CO2 comes on.

My discus have never had a problem with it, plus it saves CO2. There is no need to have the CO2 on 24hrs. You can also run an airstone when the CO2 turns off if you need to.

Dave.

[Bad Inferno]

So does constant ph really matter to discus ?...with what your saying probably not and I have not noticed any behavior differences in mine since I lost co2.

Although I will get the bottle filled this week as my bottle lasted 2 years.

cheers

[Stingray]

Davo wrote "plus it saves CO2". I am not so sure about this. A ph controller usually does not
dose CO2 for the full lighting cycle (ie, perhaps it might dose for 6h out of a 9h lighting cycle),
and at night the CO2 controller will rarely dose CO2 (perhaps 3h hours out of 15h). I think the
amount of CO2 being used will be similar, however the 'ph controlled' method will give more
consistent and beneficial CO2 levels. In fact, from my own observations on one of my tanks
I have found that the ph controller actually saves CO2. I guess it depents on the actual needle
valve setting (ie, bubble rate) and your the ph swing tolerance you have allowed for.

[len]

Hi

I do not have money for a CO2 computer at the moment so when for a manual presurised system, how many bubles per minutes should i strart with? kH is 3 and PH 6.5

I also do not have a autoswitchoff at night. Is this nessasery?

This is my discus tank, so very worried i will kill them!

[Stingray]

12 - 15 bubbles per minute (which equates to a bubble every 4 to 5 seconds) would be a good start. Although others might have a different opinion ?

[ryan]

bad inferno - how do you collect that data, I would be interested to know - very impressive!

[Bad Inferno]

ryan...You need monitors that provide an output so that you can collect the data.

I use 2nd hand ph & conductivity monitors from ebay that enable you to set not only relay outputs to drive solenoids however have a 4-20ma output that represents the reading. You then have many options that allow you to collect the values via a data logger

This is a similar unit however for resistivity, they sometimes have PH and conductivity however you can see the type of instrument it is.

http://cgi.ebay.com/Foxboro-873-Resitivity-Analyzer-Conductivity-873RS_W0QQitemZ270060036526QQihZ017QQcategoryZ7818 3QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Do not buy these devices if you are unsure of powering 110VAC devices. ALso you need a suitable probe.

rob

[ryan]

thanks for the info ill check it out

[Nathan]

i disagree stingray, i started with a bubble every 2 seconds then worked from there.

most ppl say start with 1bps but a better idea is to start off real slow.

[diveboy]

Thanks for replay via PM Rob,

I've found this little PH to USB interface, wonder if we can hook that to a ph meter and just use that for data logging ?

http://www.active-robots.com/products/phidgets/ph-sensor.shtml

they also have a K-type thermocouples to usb as well.

provide an API for lots of languages. wondering if we can find a ph sensor to plug in and do some home brew development ?

[Bad Inferno]

Wow I had looked at phidgets before however never seen the ph device. If you found a pH to 0-5 VDC device, I can help with getting that into data logging software....and duplicating what I have. I run a small web server $130.00 + Hard Disk to do data collection. (don't need PC).

where are you located

[diveboy]

western suburbs Melbourne.

sys admin/project engineer/programmer by trade, so processing the data once it's in the PC should be easy enough. just not that up on electronics.

will fish around and see if I can find something.

I looked at the Canadian site for the phidgets, it's AU$99, compared to AU$150 from the UK.

so, if it's possible, I want to set up some monitor that will do ph, inside tank temp, outside tank temp and possibly some servo control for co2.

but will start off with the ph sensor.

who knows what this could be the start of; if we can get the plug bits for this.

[ryan]

good find diveboy - heres a company that we have used in the office (im in IT for a manufacturing company) http://www.datataker.com.au/ Ill have to have a look around the office as I remember a few years ago having a USB type logger, this may work perfectly with the sensors you have found - the problem was at the time there were no USB sensors around?

looking on the site now they have many newer models - though from memory they werent the cheapest going around - there may be better options?

bad inferno - what device do you have for the webserver - is it part of the logger or and addition on that?

[diveboy]

good find diveboy - heres a company that we have used in the office (im in IT for a manufacturing company) http://www.datataker.com.au/ Ill have to have a look around the office as I remember a few years ago having a USB type logger, this may work perfectly with the sensors you have found - the problem was at the time there were no USB sensors around?

looking on the site now they have many newer models - though from memory they werent the cheapest going around - there may be better options?


ryan, with that usb phphidget sensor, you can access it directly via USB, no need for an interface box. I found the manual for it, they list a couple of pH probes that are known to work with it. http://www.phidgets.com/documentation/1058.pdf

[ryan]

your right - I was just having a look at the same document

[ryan]

theres no mention of the devices supporting snmp - bad infereno - is that how you have yours setup?

[diveboy]

they won't support snmp as there is no ip stack on them.

but I could write a phidget to snmp server pretty easily.

thats if you wanted to keep it as a passive logging system. you can control 240v power points thou with the 8/8/8 interface and the dual relays.

I'm going to order the ph sensor and the temp sensor and knock up some homebrew data logging as a play over Christmas.

[Bad Inferno]

Diveboy....WAIT !!!! Don't order just yet

[diveboy]

ok

I don't have a tank yet, it's on order since I cracked my other during the move.

I'll wait for further info.

[Bad Inferno]

Check out a package called owfs

1wire is the answer to low cost networking of devices.

Hardware platform AUD140.00 + any old HD
http://www.owfs.org/index.php?page=nslu2

I'll PM you tomorrow with my network diagram...

[diveboy]

the slug pops up again.


already got 1 slug overclocked with a TB hanging off it.

I have a few spare laptops hanging around doing nothing, hence the freedom to code a win32 app to do what ever.

I thought about using the slug as a usb to ethernet interface, but a bit rusty on my C.

As long as I make my code "protable" there won't be a problem moving it to the slug.

really, all I need to know is.

is the phidget range of devices suitable for building a tank montioring system with the view to implementing a tank controller in the future ?

given that the other cheaper option is the Aquatronica AQUARIUM CONTROLLER SYSTEM, which is out of my price range to begin with, well out of my price range I want to spend for keeping fish.

[ryan]

there has to be a better (cheaper) option than the aquatronica option

[Bad Inferno]

I/O Control...If you can write a driver for the phidgets that would be great and I will be very interested if I ever get to my EPIA board option.......The main draw for Phidget may in fact be the ph interface they provide however if you can get a ph - 0-5VDC interface I think 1wire may have a couple of advantages for the non-programmers of the world like me :).

I would like to be able to monitor and initiate water changes over the internet however also want it 100% safe. I currently have solenoid valves for my drain and fill system on my tank and have thought very hard how best to control them automatically. I have come to the conclusion that neither 1wire or Phidgets or any USB digital output devices should control the solenoids directly however be an input to another device. For my application I am going to have the 1wire output switches as input to a PICAXE control chip. A PICAXE is a very easy to program "chip" based CPU with 4 to 40 I/O. This means the controller will tell the PICAXE to complete the water cycle and the PICAXE will then control the solenoids. PICAXE is a very reliable single chip device, and can do things like limit the time the solenoids are ON, do not allow consecutive water changes, and more importantly don't flood the house. there are too many things that could go wrong with the SLUG/Laptop, 1wire/USB-phidget board or if controlling over the internet the loss of access into the system. under the "equipment" forum you can see my first aquarium controller based PICAXE/LCD together with the solenoids and current manual override switches for the solenoids.

Hardware Options

Laptop...If you have one why not use it ...although it does require powering 24/7...I think the real benefit of using a laptop is the ability to add an 8" LCD screen and place this on top of the tank....It can display all parameters, touch screen control, and maybe even double as a digital photo frame.

EPIA Board...If I had the money I would use one of these VIA motherboards which is an all in one nano type (very small) motherboard with embedded CPU, video etc etc..it also has USB serial..The drawback is powering these devices, as the PS generally ends up larger than the computer.

NSLU2...Aka "SLUG" cannot connect to a colour LCD screen however does provide a web server that you can display everything through html pages. Major benefit of this is costs and physical size and power requirements. I use this and have connected a 1wire network of interface devices. I currently measure ph, cond, tank temp, ambient temp, outside temp, water level in reservoir and just installed a flow meter on my drain line. 1wire devices are cheap and you can connect more than enough devices to a pair of wires. ie each digital temp chip is $5.00, a 4 channel voltage input chip is $20.00 and there is also a 1wire LCD panel which you can also connect. There's probably 20 different devices you can buy for 1wire. My Slug runs the 1wire interface, Synchronises to NTP (World time), collects and trends data, emails alarms and serves this data via a its web server. You do need to know a few linux comamnds however all the above gets done in maybe 4 simple script files and a web page front end. You can also get some pretty cool 1wire weather stations, that monitor rainfall (probably not required at the moment !), humidity, temperature, wind direction, wind speed, atmospheric pressure that you can connect up to your montiroing systems as well as your aquairium. Just monitoring ambient temp and tank temp on a chart you can get to see the direct relationship....

WRT54G...Is a wireless router that you can also connect 1wire devices to for monitoring. Using this device you do not need to run any wires to your tank...It just uses wireless ethernet between the router and your PC. As this device does not have a hard disk you still need a PC or something to log the data continually. Thus NSLU2 is probably better.

MAYBE we should move this thread out of "Gardens"

cheers

rob

[diveboy]

I was thinking the same.

For all further chat about monitoring, sensor development please use this thread http://www.discusforums.com/forum/viewtopic.php?t=10364