Ph probe for calcium reactor

[AlexR]

So I am finally hooking up my korallin c-1502 calcium reactor. It’s been sitting in my closet for years...

I have a PH probe in my DT and am adding another PH probe to the calcium reactor.

I can control the calcium reactor using my reef angel controller.

My question is what PH should I aim for in the reactor itself?

My DT’s PH has been quite low recently. Swings from 7.5 to 7.9. So I just started adding some kallwasser to raise it a bit. And it has been working. Slowly. Got it to a high of about 8.2.


My calcium tests are also reading low. About 360 with a dKH of 7-8. Everything is a bit low...

Although my magnesium is quite high at about 1700-1800.


My goal is for a PH at 8.4 peak. So from 8.0 to 8.4 is what I am aiming for.
Calcium around 420
dKH around 11


I have tried just about everything before adding the kalkwasser.
Opening windows, air stone with outdoor air source, opening cabinets, increased water surface movement, etc... They did not help.

[otimer]

First you'd rather confirm the accuacy of pH measurement and/or calibrate the probe.
Also all test kits must be proved their accuracy before you take actions.
Then take half gallon of tank water and airate it with an air stone for couple of 10 minutes at out side. The pH must be above 8.0 as the alkalinity is about 7.0~8.0dkh. If the tank water is so natural and pH probe is accurate, the pH must be arround 8.3 or a little higher.
If pH is lower, something in your tank pulls down the pH low. Somthing is decaing or is releasing chemicals that make lower the pH. You must find the reason first.
Good luck~!!

[AlexR]

The probe is calibrated using the 7 and 10 solutions.
I have moved the probe around from the refugium to DT with minimal to no change in the reading.
I have tested the probe in the solutions and they read correctly.
I have tested my water in a cup out of the tank and it reads higher.
Test kits read ph higher but I’ve been told ph test kits are useless.

I’ve stated other things I have done in my OP.
I’m sure it’s not stray voltage as everything in my DT is DC pumps and also a grounding probe in both my DT and refugium.

I have sufficient aeration. Considering the ATS in the refugium , a jebao 15000 return pump that is more then sufficient with surface movement, air stone with outside air source.

At this point I am stumped.

The tank is about 5 years mature now.

[otimer]

I understand you have done every thing you can do, and the pH probe is accurate enough.
Even DC pump can release stray current, but battery operated pH instruments are not affected by the low stray current from a DC pump.
In conclusion, room CO2 is not the reason for the low pH. Thus somthing in the tank/system absorb H ions (This is same as some chemicals are lowering pH).
In my understanding, old substate can pull down pH for example.
If you dose kalkwasser for adequote pH without eliminating the cause, alkalinity and calcium will go up too much. If you aim the alkalinity and calcium, the system pH will not go up sufficiently.

[hkgar]

PH is a brat. It will and does what it wants and you have very little control. Only by decreasing CO2 can you increase PH.

Just leave it alone. It has no effect on anything and as long it it is above 7.5 you have nothing to worry about..

Set the reactor control to shut off the co2 is ph <6.35. The reactor will settle in at a level ph. Ideally somewhere betwenn 6.5 and 6.8. If you need to increase the dKH if the tank lower the ph by adjusting either the CO2 bpm or the regulator PSI .

[AlexR]

My pH probe is finicky at best.
I have a 2nd probe on order. They both hook up to a reef angel controller.

I was gifted the reef angel and it was my first ever controller. So I added and added to it.

I kinda wish I started with an apex but I’m making the best with what I got.

I just recalibrated the pH controller yesterday and got the same readings... pH at 7.6 or so and peaks at 7.9 to 8.0 if I’m lucky.

I know it’s finicky because when something (like the wire) moves around the pH drops to 5 and slowly (hours) raises again. Maybe the 2nd probe will be more accurate.

I know not to chase it too much but it’s frustrating seeing numbers like that.

I’ve made the mistake before trusting my salinity probe without double checking with a refractometer. I raised the salt to about 1.032 and nearly killed my pincushion urchin. Luckily I caught it quick and fixed the salinity.
But it was a lesson learned. Never trust just one source of information...

Anyway I will be hooking up the korallin c-1502 next week, after some replacement parts come in. It’s been in a closet for years and the plumbing is cracked on the inlet and outlet, I got a new lid with the probe hole and a new eheim pump.

I hope the calcium reactor will help keep my levels umm — level...

I don’t have a huge amount of corals yet. I don’t want to experiment with living organisms. I want to have everything check out right then I will start stocking with some amazing stuff.

[AlexR]

It’s funny. I post questions and kind of already know the answer. It’s usually just common sense for someone in this hobby for over 2 decades.

But I ask anyway thinking I may just be surprised...

[otimer]

I was gifted the reef angel and it was my first ever controller. So I added and added to it.
.[/QUOTE]

I misunderstood you are using a battery operated pH meter. If the pH readings are from a controller that is powered by AC, electrical noise must be checked. If the cable of probe is wired parallelled along with an AC power cable, faulty readings can be made due to electrical noise.
Cable sagregation is important in this case.
If the readings change, when you touch or reloute the cable, may be it is due to electrical noise. This can be confirmed that the reading will be different when you measure the pH of tank water in a cup away from the system.
I resolved this noise problem by segreating cables and installing ferrite cores on the probe cables.

In many articles, they say srony corals are difficult to build up their scaleton under pH 7.8.

[AlexR]

That’s a good tip thanks!

I’ll try adding a ferrite core to the ph wire and will segregate it. That may just do the trick.

[AlexR]

Well just my luck...

Figured out my ph probe is faulty and that’s why my readings have been off. Eventually it just stopped working at all.
It was showing strange behavior. The ph probe was working out of water and in the calibration solution but stopped reading completely as soon as it touched my tanks water.
It was a new probe which was never left out of water for more then a couple minutes.

Have a new probe on order. And a replacement probe coming in. So I will have a backup probe just to be safe.

Still waiting for replacement parts for the calcium reactor. Can’t wait to get it up and running.