Not sure about the PH20 myself. Perhaps we have the wrong model number. It's $66 and their cheapest. Forget the price for a moment. It's their cheapest. It uses the small probes found in the $5 meters and in the $10 one's where it can be changed. They call it propriety, which is another way of saying non-standard.
The probe is the fancy bit of a meter. People are buying in probes from the probe factory and sticking them in their own cases with their own electronics. I like that this case is waterproof and the screen looks alright. The probe is bargain basement though.
The $105 PH60 uses an industry standard probe. Their display is 0.1 accuracy but the probe is 0.01 which is 10x better than in the PH20. I can't be sure, but I think that probe looks a lot like many use, including my own very different looking meter. It's because of supply chain.
If you look on Ali you will see the PH20 I think. That bad probe and cheap green plastics start to narrow it down. Look at the batteries it comes with. That is $20 while the PH60 is a real meter.
I looked an Ali, and actually you won't find them green meters now. Things have moved on. Meters there rarely cost more than $20 and for that you get a combination meter that bluetooths to your phone where all values and alarms exist.
https://www.aliexpress.com/item/1005...01373700_2&s=p
If you want branding the H&M can reach $40 and are a perfectly good meter. There will be some bad reviews as all these meters suffer overnight if you leave the lid off, and people do so all the time. I have worked with people who claimed never to, but I found the thing off every week almost. Oddly.. they were just in the middle of doing the tank. Yet it was dry as a bone. Idiots.. salting the probe up and blaming the tools. I don't remember how old my meter is. At least 10 years old. Anything you can't buy for $3 will last if you treat it right. While some claim nothing lasts 3 months. The local shop must change it's meters every few months to not be seen as selling rubbish, and 'level' with some customers that they sell hobby meters, and should spend £300 (if they want the manufacturer to supply a new probe every 3 months) And join in with the customers complaints that you just can't get a good one.
The best advice is to view them as disposable. Don't expect to find new tips when you want one, unless you buy from a scientific supplies company. Do get one that looks like the tip can be changed though, as it's probably a good sign. Especially with that 0.01 accuracy claim.
Regarding scientific supplies companies. They will sell you a $50 Hanna for $150 because they keep to standard lines and stock the spares. You will pay for such professionalism.
Hanna and eutech drift down to us if you want branded stuff. While you can easily spend $300 on something that you thought was $50 if it says cole parker on it, or fisher.
In hydroponics we find lab grade stuff coming from N.Z or BlueLab and priced between Standard stuff and Lab supplies.
The single biggest part of having a good meter, is treating it right. If you loose or bust that plastic cap, it's dead. All you need do is shake off any drips and put the lid on. Without good practice, the $300 meter is no better than the $10 meter.
