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Replacement Ph probe for Dennerle


29 Mar 2008
So eventually it's taken me long enough to start looking at planted tanks, tropical fish keeper all my life grown plants here and there, but not a planted landscape, so eventually started with a Nano 20L tank to experiment with before moving on to larger systems.

Anyway, I'm fortunate to come across original new and boxed Dennerle Systems, purchased in the 80s, all complete - I've got quite a few but for some reason I cannot find any of the Ph electrodes, I've even to this day, got CO2 Dennerle tanks FULL, bolted to the fish house wall, when I relocated it, over 20 years ago! (never used full, still good pressures are good).

I've got the early green Ph Controller Comfort, not sure if relevant today, but If I've got them I might as well use them, of take them down the tip.

Considering the current price of Dennerle Ph probes, at £89+, and these units may be duff, don't really want to waste money, anyone found a cheaper replacement probes, e.g. Aqua Medic or IKS replacements ?

are these the same ?

a Ph probe is a Ph probe right ? (flame retardant pants on!)
Do they have a BNC connector? If so any probe with a BNC connector will work. Only difference might be that a cheap one isn’t as good quality.
yes, it has a BNC fitment. The Dennerle specifications also states good for other devices! Ordered a cheap one from Amazon, I can return if crappo!
I've used the $ 7 to $ 9 Refillable China probes for quite some time on a Milwaukee and a Hanna instruments and wasn't really disappointed. They are refillable and mine came with a small syringe and a small bottle to make new reference fluid. Didn't use them much longer than 2 years and did fine all this time. One of these went to a friend and he's still using it on his swimming pool till today.

Comparing this price wise there is non to complain. They are equally accurate as their expensive cousins. Buying 10 for the price of 1, who gives a darn if it doesn't outlive the expensive one.

Even with the expensive top brands, it is advised to replace the probe every 12 months... Also, this is rather questionable and likely commercial advise. I've used such a probe much longer several years, than I stored it for about 6 years, dug it up again. Tried it and it was still OK to use and again used it a few years... Just don't fix what ain't broken... I guess the manufacturer advises is aimed towards the worst-case scenario use in rather abrasive and aggressive solutions. Tap water isn't and is very mild on the probes.

When it comes to accuracy we get a runaround anyway, I've used 4 different correct calibrated pH probes simultaneously and all still gave a slightly different value from the same water... :angelic: Than it's pick one you believe the most. Whoever believes is blessed... :cool:

Thanks for the reply, I think what we are generally noticing over the years, as some items were specialist and difficult to obtain, and a massive markup by manufacturers, most things manufactured in China, and many years ago before opening up of China, Internet, ebay, Bangfood, Aliexpress and Alibaba, items become easier and cheaper to obtain.

It's great to here, I've got a Hanna instruments Ph device as well, so worth a look at these as well.

I've got IKS units, which need new probes. I think any measurement system you use varies, I've seen the same with temperature probes as well.
@zozo I can never seem to find these for a throw away price so use the sealed probes, do you have any links for the refillable ones

The one i linked to in the previous reply at the bottom is the one I have... :) Here is the link again.

The grey coloured ring at the top has a tiny hole, it can be turned to close or open and refill the probe. I'm not sure if all probes offered come standard with a refill, mine did... That was a small bottle filled with a white powder, you need to add a few ML distilled water and the solution s ready to insert. I forgot how its named. MOL something i remember... :)

I used it like this

On this scape and i have nothing to complain actually..

But that might be different in the way you use a controller if the controller is used to shut off CO²... But that's a different story... :)
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