reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[AbjectMaelstroM]

This post might help you.

You are 100% correct. That was exactly what I was looking for.

Thanks!

 

[AbjectMaelstroM]

Wow double check your wiring and grounds. This is very strange that the light does this without any power. Did you get a hot and neutral mixed up on the 120v outlet side maybe? I dont see how the light would cause this without any power going to it unless its getting a leakage current somewhere.

I unplugged and plugged everything I could find....and it's all working. I guess time will tell.

Now I need some pH calibration fluid.

 

[raketemensch]

Got my relay all set up and tested today. Took quite a while to wire everything, but it was totally worth it in the end.

There’s some aquarium silicone drying on the temp probes, then tomorrow they get recalibrated and everything finally enters the tank.

still gotta order a ph board and probe, and set up the Mars Aquas, but one step at a time, right?

 

[AbjectMaelstroM]

While I wait for pH calibration fluid.... Is there a way to convert the raw probe reading (mV?) to aprox pH?


Think I found my answer, unfortunately I don't think it's going to help much. The conversion is on the scale of - 400 to 400, 0mV being 7pH.

My probe is outputting ~ -5934....so like it or not, I'm going to need calibration. Or my probe (which arrived dry) is kaput.

 

[Bigtrout]

While I wait for pH calibration fluid.... Is there a way to convert the raw probe reading (mV?) to aprox pH?


Think I found my answer, unfortunately I don't think it's going to help much. The conversion is on the scale of - 400 to 400, 0mV being 7pH.

My probe is outputting ~ -5934....so like it or not, I'm going to need calibration. Or my probe (which arrived dry) is kaput.

The numbers do not correspond to millivolts directly. If i plot my calibtation out -6000 corresponds to a ph of 8 or so so it may be just fine

Some numbers for reference:

My raw numbers were

Ph 4.01= 20260
Ph 6.86=195
Ph 9.18= -16460

 

[AbjectMaelstroM]

The numbers do not correspond to millivolts directly. If i plot my calibtation out -6000 corresponds to a ph of 8.2 or so so it may be just fine

Huh, cool. I just did the traditional red sea pH test and the color was close to 8.2

At least gives me a point of reference.

Thank you.

 

[Bigtrout]

Huh, cool. I just did the traditional red sea pH test and the color was close to 8.2

At least gives me a point of reference.

Thank you.

It will really help to get 2 points of reference but let the raw numbers plot out for awhile to see how stable it is.
My ph varies about .1 to .2 ph over a day because of the plants using up co2. Reef tanks experience a similar cycle

 

[AbjectMaelstroM]

It will really help to get 2 points of reference but let the raw numbers plot out for awhile to see how stable it is.
My ph varies about .1 to .2 ph over a day because of the plants using up co2. Reef tanks experience a similar cycle

What two point of calibration are people using? 4/7, 7/10, 4/10?

My thought was 7/10 since where the typical range falls for reef tanks.

 

[Bigtrout]

What two point of calibration are people using? 4/7, 7/10, 4/10?

My thought was 7/10 since where the typical range falls for reef tanks.

Perfect
Because im right aroynd 6.8 to 7 ph i tested all 3 points and didnt see a difference enough to worry about between testing at 3 points and testing at 2. Youd be fine to do 7 and 10 on a reef tank

 

[Schreiber]

Speaking of pH calibration, what ever happened to the 3-point option, @Ranjib ?

 

[Bigtrout]

Not needed!!!
It is close enough with 2 point cal.
3 point cal is lab grade stuff...and calculating slope on 2 point vs 3 point is almost pointless for the accuracy gained.

The only way 3 point would be needed is if you buy lab grave probles

 

[Schreiber]

Not needed!!!
It is close enough with 2 point cal.
3 point cal is lab grade stuff...and calculating slope on 2 point vs 3 point is almost pointless for the accuracy gained.

The only way 3 point would be needed is if you buy lab grave probles

Ah, gotcha. Yeah, I didn't mind it disappearing which is why I hadn't asked before. I figured that the slope would be relatively linear. Just thought I'd ask while the thread was on the topic

 

[Bigtrout]

Ah, gotcha. Yeah, I didn't mind it disappearing which is why I hadn't asked before. I figured that the slope would be relatively linear. Just thought I'd ask while the thread was on the topic

No prob...the slope is very linear...the only real diifference is the offset per probe

 

[Ranjib]

I think the pi B has different gpio drivers than recent models so it won't work. You can get pi zero w for $10. Less power more compact.

Pi b will work just fine. Instead of pi 3 build use the pi zero build. It’s based on arm6 architecture, that’s all . Let me know if it does not work , I’ll check it out. But I personally tested once and all pi zero build will work on pi b

 

[Ranjib]

What two point of calibration are people using? 4/7, 7/10, 4/10?

My thought was 7/10 since where the typical range falls for reef tanks.

7/10

 

[Ranjib]

Speaking of pH calibration, what ever happened to the 3-point option, @Ranjib ?

Seconding what @Bigtrout mentioned. After reading through some docs I felt it’s not required. If you encounter evidences that indicate otherwise, please share , I’m happy to do the right things

 

[Ranjib]

Does anybody know if reef pi works with a Raspberry pi B rev2? I can get the web GUI running but none of the IO work. Not even test LEDs.

Do you have a build thread. We’ll need details including your setup and test circuit etc. please start a thread with the details that we can read through and answer.

 

[Ranjib]

No prob...the slope is very linear...the only real diifference is the offset per probe

On this note, I’d love to assess the impact of temperature compensation .. may be sometime in future

 

[DirtDiggler2823]

Has anyone tried the Noopsyche lights to their reef-pi yet? If so, what cables did you have to build? Looking at getting some soon and I'd love to tie them into my controller.

 

[AbjectMaelstroM]

Took a peek at the ph reading this morning and looks like there was a pretty big (or at least looks big) drop, about 500-600 points on the raw reading scale. Broke out the red sea test kit and it kinda looks like 8.0 so about 0.2 drop overnight.

Interesting to see if it climbs back up throughout the day. Kinda looks like it's already starting to climb.