Backyard Aquaponics
A place to discuss aquaponics

Hey check out these constant digital PH meters with alarm.

http://www.hannainst.co.uk/acatalog/cop ... alarm.html

HOW MUCH???
Have a look on ebay ..... PH DS TEMP and ??? $99.

Yeah - I spotted those too - $79 USD for a lot more measurements.

http://www.gainexpress.net/dotcomhkshop ... ucts_id=52

I get what the PH and temp are.

I even get that TDS is - I assume it is Total disolved solids.

But what is EC and CF?

Yep on TDS ,, I think the other one was CF.
I'll go check and come back with a link to the ebay product.

EC is electrical conductivity? hydroponic stuff

Yep EC ,, I know it's considered a hydro test ,, but surely it is helpful as an idictaor as to whether AP er's have a good bal;nce of plants/ fish??? That's a question as I do not know.

Here is the link to the product I am interested in ,, it can easily be hooked into a PC or PLC.
http://cgi.ebay.com.au/ws/eBayISAPI.dll ... :IT&ih=022

I'm lost Chappo..... just what are/do you want to measure... and do you understand what the relevant "tests" actually measure....

pH and temperature are important..... but an equally or even more, important test and measurement in a "recirc" system (like AP) is Ammonia (as it is in aquaculture) and nitrites....... or even DO....

The listed meter can't do any of the most important tests that AP or even aquaculture require.....

Ans if you're running a hydro application.... then you'd buy a rock solid "BlueLab" Truncheon to measure those variables.... for the same price......

P.S...... EC/CF are both PPM measurements.... just different scales.... it's really only an expensive thermometer and pH meter....

Rupert , I am trying to measure nothing. I was in fact trying to help a fellow AP'er that was interested in buying a PH tester alarm at an expensive price.
I merely pointed out an alternative that not only measure PH but also measured other variables.

Sorry Chappo, must have read it wrong.... Knew Hamish started the thread about an "alarmable" pH meter ....

Just saw this part of your post .....



.... and thought that maybe you were going to get one to use as a datalogger to input to your PC or to some sort of PLC controlled valves/doser..... whatever..... wondered what you were trying to measure and why?

No worrries mate ,, I've written to the same company that produces that meter and asked if they have a PH , TEMP , dissolved oxygen , nitrie meter available , or in fact could they build one at a good price for APer's.
I've been looking around for a good cheap meter that covers the basics and can be hooked into a PLC or PC or lap-top.
I realise many on this forum need cheap alternatives , so I was hoping to come up with a fully intergrated monitoring system inclusive of alarms ( yes even loss of power alarms) for under $300. It seems feasible ,, I can get PC's for less than $70 , software looks easy , its the meter that's proving hard to get at a good price.

..... been the lament of every APer here since the inception of the forum Chappo......

Let us know as soon as you get one .....

A few words of caution about inexpensive meters!!!!! They are more likely to fail or go bad or whatnot. A failing meter can cause worlds of headach as one tries to adjust the pH of a system but the meter is telling the wrong thing. I've done it in Hydroponics and it wasn't pretty. At one point in time I thought a meter would be better than papers or drops since you don't use a meter up each time but then I found that you needed to buy calibration solutions, and storage solutions, and cleaning solutions, and replacement probes, and then the meter went bad anyway.

If some one is putting in a large comercial system, they will probably need to get everything all wired up with automated stuff.
For a small backyard system (unless one is really into playing with the automation stuff for personal pleasure) one is probably far better off sticking with the old fashion drops and testing by hand.

I expect that for most of us, an alarm to notify if something goes wrong with the pump or water level or perhaps even temp is far more important than an alarm for pH. (Then again, my system is full of sea shells and it would probably take a vinegar Tanker spill into the system to budge my pH so my opinion is biased.)

The PH, temp , is no probs,..... getting the nitrate / oxygen at a reasonable price is the problem.
I am tenacious , some would say pig-headed, but that trait can be used for good

Nitrate is pretty straight-forward with titration kits

Cheap DO readings is the sticky point.