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Seneye

tubamanandy

Member
Joined
28 Feb 2013
Messages
362
Location
Thornton, Lancashire
A warning:-

Up until very recently I wasn't aware that my Seneye Reef was unable to give me correct PH readings as my KH is always <7 (usually 4-5). Great thanks to a fellow poster for letting me know about this.

As I couldn't find anything about this in their literature when I bought it, I decided to drop them an email a few days ago. Whilst not actually confirming the above, they used every excuse under the sun to say that many electronic meters cannot read PH values in low KH water.

After a couple of emails they asked me what equipment I was using to measure my PH other than the Seneye. I told them it was my Pinpoint PH meter calibrated to PH7 recently and a newish PH test kit. PH meter gave a reading of PH 6.4, test kit about 6.4-6.6 and Seneye meter 7.17.
As soon as I gave them the above information they broke off contact with me and never came back to me.....not exactly inspiring confidence. I still use the meter for temperature & PAR/LUX readings but I'm very reluctant to pay £6/month anymore for slides. Not happy
 
I had pretty much the exact same experience as you mate. They know they've screwed up- I could tell from the way they were acting.

It really should be made clear before you buy the expensive bit of equipment that it is actually incapable of measuring pH in soft water.
 
It's sad that their pH readings don't go lower than 6.4 too. My high-tech tank with CO2 injection and ADA Aquasoil goes lower than that. I stopped buying slides. I just use it for the PAR/lux/kelvin meter really.
 
Like I said in the other thread, for the last two (?) years or so, they have been promising:

1) a low pH slide

2) more parameters like nitrate and chlorine.

All of these things are "coming next quarter". They have been coming next quarter for the last 7 quarters, so I'm not holding out much hope.

Greg at ADC is my main point of contact because he is in direct contact with the main man at Seneye. We always have a joke about them whenever I go in. He said that he spoke to them frankly, and they said the slide can't measure pH in water of less than KH 7 (which has already been confirmed here). But they also said the new slides will be here in 4 months.

I'm not going to hold my breath.
 
Hi all,
Whilst not actually confirming the above, they used every excuse under the sun to say that many electronic meters cannot read PH values in low KH water.
I'm not making excuses for Seneye, and I wouldn't use their devices even if some-one gave me one, but this is true, pH is a fairly meaningless measurement in very soft water.

cheers Darrel
 
Hi all,I'm not making excuses for Seneye, and I wouldn't use their devices even if some-one gave me one, but this is true, pH is a fairly meaningless measurement in very soft water.

cheers Darrel
Hi Darrel, I am quite interested in why is it meaning less to measure ph in very soft water ? As I live in congo and tap water is less than KH 1. I use Mg and Ca to raise it at Kh 5.
Does this mean that my Ph reading are not the real values ?

cheers expert
 
Hi folks,

As this thread is entitled quite simply 'Seneye', would this be a suitable place to share our experiences about the seneye range of products?

I have a seneye reef monitor but I don't want to hijack this thread. If necessary, I'll start a new one.

JPC
 
Was the minimum limit for pH measurement a KH of 7? For some reason I thought it was 4.

I have observed, if you don't change the slide... it keeps working. I can still check the website and mobile client for updates. They still send e-mails telling me it is too hot on sunny days.

Of course, I can't guarantee the results are right. According to my client I'm now 259 days late replacing the existing slide, and it is still giving a pH reading in my marine tank (typical KH range 7 to 9). Actually I could check easily, just need to move over one of my pH probes from the tank next to it... Suffice to say, the pH value from the long expired slide is still going up and down in a daily cycle, and the values are within the expected range. I never had any ammonia so I can't comment how that performs, if at all.

I'm going to see what happens if I hit a year late on this slide :D
 
It's 5 or 6. That's the minimum. I have been told it struggles at "less than 7"

The slides only need to be renewed for text alerts. I haven't changed mine in over a year.
 
On the earlier question I had on accuracy of pH measurement, I have stuck one of my pH probes in tank near the seneye. The pH probe has been soaking a while and is currently measuring 8.05. Seneye reports 8.25. The probe was calibrated perhaps a month ago using 7 and 10 references. From memory, I think the particular probe I'm using now ran out of adjustment rage and actually was only going up to 9.85 keeping 7 fixed at 7. So it might be under reading by 0.05 or so assuming it is a linear error. Not sure if seneye ever gave out a measurement tolerance on pH. I can't find any specification in a quick search.
 
Spoke to them directly as well, they promised the low pH slide almost 2 years ago indeed. About the NO3 and Cl test. It will never measure live NO3. The website suggests this, but what they're building are teststrips, you place them in the water, and after that your Seneye probe will 'read' the color and translate it to a digital number. But this was 1,5 year ago as well.

All the time, I only use it for measuring light, works like a charm and cheaper than any other device!
 
Man, I would buy low pH slides without hesitation. It would make doing pH profiles so much easier. Having said that, I think the Seneye is a cheap and effective PAR meter.

P
 
Hi all,
it is still giving a pH reading in my marine tank (typical KH range 7 to 9)
It should carry on giving you a fairly accurate measurement in sea water.

There are two problems with pH probes as you approach pure H2O.
  • The first is that pH probes are "combination electrodes" that function as a galvanic cell. This means that as the conductivity of the water falls it takes much longer for the pH reading to stabilise. This is why you can get a more stable reading of pH by adding a neutral salt like NaCl to the water, this just raises the conductivity, but doesn't add any H+ ion donors or H+ ion acceptors. Sea water is about 53,000 microS, so conductivity isn't a problem.
  • The second problem is that pH is a ratio of the acids:bases. Because pH is a ratio it doesn't tell us anything about amounts. To use an analogy where sugar represents both acids and bases, if you have scales with 1 grain of sugar in the "acid" pan and 1 grain of sugar in the "base" pan you have pH7, if you have 1 cube of sugar in either pan you have pH7, and if you have 1 kg in either pan you have pH7. The pH is the same, but in reality they are very different situations.
Heavily buffered, high conductivity systems (Marine, Lake Tanganyika) will give you accurate alkaline pH values, but as you lose buffering and conductivity pH measurement with an electrode becomes more and more difficult, and really only titrimetric methods (where you add a known volume of a known strength of acid (or base) to your water and measure the colour change in an indicator compound) work.

A drop checker is actually a titrimetric method using the experimentally defined pH values from the dKH~CO2 equilibrium as a datum. In the drop checker you are adding an acid (carbonic acid (H2CO3) from added CO2) to a base (4dKH "water"), and observing the colour change in a narrow range pH indicator (bromothymol blue).
It will never measure live NO3. The website suggests this, but what they're building are teststrips, you place them in the water, and after that your Seneye probe will 'read' the color and translate it to a digital number.
Yo-han is right, ion selective electrodes aren't accurate where there are other anions present. The NO3 test papers again are actually another semi-titimetric method with the Seneye device working as a colourimeter.

These devices are fine if you like bits of kit, but they aren't ever going to tell you anything really meaningful about your water, unless something really strange has happened, which presumably you would have noticed anyway.

cheers Darrel
 
It's 5 or 6. That's the minimum. I have been told it struggles at "less than 7"

The slides only need to be renewed for text alerts. I haven't changed mine in over a year.
Hi Sacha,

I was told that a KH of 5dH is fine but to avoid going below this. There was no suggestion that it struggles at less than 7. From what I can gather, a guy there called Mark is the designer of the seneye sensor. The whole team is only a handful of people. My guess is that it depends who you talk to as to what answer you get.

I had no idea that the slides only need to be renewed for text alerts. That doesn't sound right to me. One half of the slide is in permanent contact with the aquarium water. Its properties must surely change over time?

JPC
 
The Seneye uses a colour changing indicator for pH, so that may behave differently than a probe. I'm surprised it hasn't worn out totally by now, such as by the indicator either wearing out or simply washing away. Fortunately in a marine tank, pH isn't a critical measure, in that if you take care of KH, the pH will largely take care of itself. I have used the reverse, in that is pH is drifting lower, it means I haven't been topping up KH enough recently.

I think in part they recommend a monthly renewal of the slide to make sure it is fresh and accurate. Readings after that time are more of an unknown. As mentioned before, I had a look and so far haven't found anywhere where they state an accuracy for any of the measurements even with a new slide. At least in reading the manual I found out you can turn off the annoying flashing lights so I might return it into a display tank some day.
 
All the time, I only use it for measuring light, works like a charm and cheaper than any other device!
Hi Yo-han,

I have the reef monitor and use it for light measurements - particularly PAR. But it frustrates me that, when attached to an aquarium panel, it can't do this because the light sensor receives less than 1% of the light entering the water from above. A design flaw if I ever saw one! I suggested a possible solution to seneye but perhaps I need to rig something up myself. Have you found a way around this?

JPC
 
Hi Sacha,

I was told that a KH of 5dH is fine but to avoid going below this. There was no suggestion that it struggles at less than 7.

Correction:

Here's the email they sent me a couple of years ago.

Hi Sacha,


I think that we may have send this to you before, but in your KH level of 5, all pH measurement methods will struggle to read consistently. The link below explains this in some more detail.


There is of course slide to slide variation. We see a worst case of 0.15 +/- with the standard distribution being far more closely matched.


I think that being at the lower end of the KH measurement, and towards the extremes of where the seneye measures you are seeing a combined effect. Whist we have never seen this level of differences between sensors in testing it could just be a case that you have had sensors that have read lower that the original one.


The low range pH sensors will be far more suitable for the pH that you are working in as they will be in the middle of the sensors range.


Until you have used the slide that we sent you we cannot make a judgement of the pack that you are using.


There is not a difference in the slide that we send with the device and the packs of 3 that are bought.


We will know more when we you fit the slide that we sent to you.


Best regards,


seneye support
 
Hi Yo-han,

I have the reef monitor and use it for light measurements - particularly PAR. But it frustrates me that, when attached to an aquarium panel, it can't do this because the light sensor receives less than 1% of the light entering the water from above. A design flaw if I ever saw one! I suggested a possible solution to seneye but perhaps I need to rig something up myself. Have you found a way around this?

JPC
I don 't thinking this is a design flaw. Keep in mind that if the sensor was in direct light all the time, algae will build up really fast. Especially with calcious algae in reef tanks it will be a real pain in the *ss to clean the plastic sensor again without scratching it.

You can use it to measure PAR on certain spots and the fact that the light sensor measures continuously is more to see when your lights turn off due to a power outage or something.
 
makes me so angry that they charge you $78 just to unlock the light meter features that are already inside the device...

My Seneye Home is already a PAR/ LUX reader. In order for me to actually see those readings, I need to pay an extra $78.

Any expert hackers on UKAPS? ;)
 
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