# Measuring PAR



## Edvet (7 Feb 2014)

Is there an affordable way to measure PAR at the moment? Or use a lux meter and convert the results to something usefull?
Seeing it gets more and more attention,one would expect something coming available that a) is affordable for an amateur b) does not require soldering or arts and crafts


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## Curvball (7 Feb 2014)

The seneye device is the most affordable PAR meter at the moment - a lot cheaper than an actual par meter and has more bells and whistles too.


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## Sacha (7 Feb 2014)

Yes, the Seneye Reef measures PAR, not the Seneye Home.


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## Edvet (7 Feb 2014)

I read on the almighty interweb they seem to overmeasure par, their conversion method is dodgy.


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## Sacha (7 Feb 2014)

Everything about my Seneye is dodgy. I only use it to monitor temperature. 

The slides are incapable of measuring pH in water with a KH of lower than 7. So my slides cannot measure pH.


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## Curvball (7 Feb 2014)

Edvet said:


> I read on the almighty interweb they seem to overmeasure par, their conversion method is dodgy.



Possibly. I was supposed to test a reef version awhile ago but that never happened. Would have been good to compare it to my apogee par meter readings.


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## ghostsword (7 Feb 2014)

Best thing you can do, either you or a club.. invest on a proper par meter..


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## Edvet (7 Feb 2014)

was hoping to avoid that,
Seeing PAR is getting more prominent there is room for some consumer par meters in stead of prosumer ones.


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## Alastair (7 Feb 2014)

The seneye home can actually be upgraded to test par. Its just a case of pay a fee link it up boomph it works.  
Actually getting hold of a par meter myself next week


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## Sacha (7 Feb 2014)

Alastair said:


> The seneye home can actually be upgraded to test par. Its just a case of pay a fee link it up boomph it works.
> Actually getting hold of a par meter myself next week




Yes. But the cost of the upgrade is pretty much the same as the cost of buying a new Reef unit. 

Seneye as a company are a laughing stock. They have been promising a low pH slide and more parameters "next quarter", for the past two years. They have a team of FOUR people working for them. I have had nothing but trouble dealing with them.


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## ceg4048 (7 Feb 2014)

Edvet said:


> Is there an affordable way to measure PAR at the moment?


Yes, look at the chart shown in Dymax Tropical 36 watt | Page 4 | UK Aquatic Plant Society
It's free.

Cheers,


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## tubamanandy (7 Feb 2014)

Sacha,

"The slides are incapable of measuring pH in water with a KH of lower than 7"

Is this comment accurate or do you just not like the company ?  Are you saying all my Seneye Reef PH readings are wrong because my KH is 3 ?


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## Sacha (7 Feb 2014)

tubamanandy said:


> Sacha,
> 
> "The slides are incapable of measuring pH in water with a KH of lower than 7"
> 
> Is this comment accurate or do you just not like the company ?  Are you saying all my Seneye Reef PH readings are wrong because my KH is 3 ?




Yes. All your pH readings are wrong. 

I have been told this directly by Seneye. This comment is 100% accurate.


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## Sacha (7 Feb 2014)

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


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## Sacha (7 Feb 2014)

I subsequently called them and had a lengthy discussion about their slides capacity to measure pH in soft water. 

I eventually just asked them straight, what is the lowest KH the sensor is able to measure pH in. He said anything less than 7 and the sensor won't work.

I should also mention that this email
Is from over a year ago. See that low pH slide he mentions? Next quarter, apparently!


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## tubamanandy (7 Feb 2014)

Only 0.15+- out ?  

Not exactly a great deal to worry about ?  Hardly worth ditching the unit for is it ?


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## Sacha (8 Feb 2014)

No you have misunderstood. 

0.15 was referring to slide- to slide variation. Because I explained I was having a lot of variation between slides. 

Under 7 KH, the slide to slide variation is irrelevant, because the slides can NOT measure pH.


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## Sacha (8 Feb 2014)

When he talks about a "combined effect", he is saying that a) my water is too soft to get accurate readings and b) I am seeing the 0.15 slide- to- slide variation. 

I think you should email them yourself and ask if you will be getting accurate pH readings in your tank of 3 KH.

Alternatively, don't you have a pH pen you can use to compare the readings, if you still don't believe me?



Also:


Hi Sacha,

Thanks for your E-mail

Can you let us know the following so that we will be able to help to diagnose what is happening please?

The KH of your aquarium
What other test methods you are using to validate the pH.

We have not come across what could be described as a dud slide before. They chemistry inside should always react to a pH that is greater than 6.4. The slide works by changing colour dependent on the pH. A pH of 6.4 will be yellow, and the pH higher than 8 will appear more blue. If the slide is bright yellow, then it is likely that your pH is around 6.4. You could test the slide in some de-chlorinated tap water (assuming that this has a higher pH) if it changes colour from bright yellow, then the slide is working. 

Best regards,

seneye support


6.4 is the lowest pH the unit can register. 

6-7 is the lowest KH in which the slide can measure pH.


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## tubamanandy (8 Feb 2014)

Sasha,

Seriously wasn't aware the the Seneye device can't read PH accurately with KH under 7 - thanks for letting me know. Can't believe I didn't spot this somewhere in their literature when I purchased the device.

I'm going to cross reference the PH to see if it is even close - I mainly use the Seneye for continuous PH & temp measurement so seems a bit expensive to run if it cannot get the PH correct (the PAR function is useful).

Thanks for the info


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## Sacha (8 Feb 2014)

Mate I had a nightmare of a time trying to get the info out of them. I also had a shout about why this is not mentioned anywhere in the literature or before you buy the slides. 

If you look on their website, there is a link that says "if you have low KH click here" or something like that. It takes you to a page that explains that their slides are calibrated to work in a KH "closer to the average tank". When I asked what this meant, they explained that the slides are calibrated to work in hard- very hard water. That is for marine users and general UK tap water. They said that for people who use RO/ very soft water, we will have to wait for the low pH slide (which I doubt we will ever see). 

Does your pH reading from the Seneye move? 

I knew something was up when my Seneye was reading 7.3 forever, and my pH pen told me the pH was fluctuating between 6.3-6.7 throughout the day. 

My advice is stop buying the slides, and just use the Seneye to monitor temperature/ light/ water level. That's all I use it for. 

I wouldn't hold your breath for the low pH slide either. 

I'm sorry for being snappy earlier. The reason I was is because I had a nightmare spending hours and hours dealing with this all a long time ago- just bringing the memory back up is very traumatic!


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## tubamanandy (8 Feb 2014)

People MUST be made aware of this - I'm fortunate enough to have soft water in my area.......perhaps I'm not so fortunate now !"

Thanks for the good information


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## Sacha (8 Feb 2014)

That is what I was so angry about. I bought the unit because I wanted to accurately monitor my pH 24/7 and get graphs for it etc. On their website there is a very small link quietly hidden away which leads to a page full of vague facts and figures. Nowhere does it actually mention that the unit cannot measure pH in soft water. It literally does not say it anywhere. 

Now, I think I owe an apology to the OP for spectacularly hijacking  his thread.


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## tubamanandy (8 Feb 2014)

Looks like you are indeed correct, Seneye reading PH 7.17, low range new test kit reads around the PH 6.6 marl - nowhere near the Seneye 7.17 reading.

Just about to ping an email off to Seneye


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