ph 7.88 Alk 9.632 with new Calcium Reactor

[JordanM]

Randy or anyone else I am looking for some input.

Parameters 12/28/18
Alk 8.06
Ca 540
Mg 1320
pH 8.0
NO3 0
PO4 0.04

Turned CaRx On and Skimmer Off

Parameters 1/03/19
Alk 9.64
Ca 437
Mg 1320
pH DT 7.88
pH CaRx 6.83
CaRx Effluent 13mL/min
NO3 0.25
PO4 0.08

CaRx Reborn Media and NeoMag

Before turning the calcium reactor on i was maintaining Ca and Alk with Kalk. I knew the CaRx would lower the pH in the DT so i brought it down slowly by adding Kalk this last week so the ph did not dip too low. I want to stop adding kalk to get the ph up but what pH is to low in the DT with a calcium reactor. I know below 7.2 the SPS will start to have there Calcium broke down. From what ive read a pH of 7.8 is not unheard of in DT's running CaRx's. What has been the lowest pH that you have seen in a successful reef tank running a CaRx? Is 7.7 too low? Where would you start to see detrimental effects?
My NO3 and PO4 has also been decreasing lower then I want it so I have turned off the skimmer to hopefully get this up. I dont really want to feed more then every other day especially since my PO4 is higher then NO3 currently. I could potentially start dosing as i have pharma grade KNO3. I just sent in an ICP test as well so it will be interesting to see how that comes back. I can also start turning off the NO3 reducing systems that contain my bacteria populations. Here is a video of my setup if anyone is interested:



Ok i have been babbling a little bit so now for some more data that you may be interested in. I removed an aliquot from my tank that was at pH 7.88 and temperature of 77F. I bubbled this aliquot for 30 minutes indoors and measured a new pH of 8.08 at 71.4F. I then took another aliquot and bubbled this outdoors for 30 minutes and performed the test again and got pH 8.12 at 68.3F. Based on this data it looks like the CO2 is not being removed from the tank readily and this is what is causing the low pH as after bubbling indoors the pH rose 0.2. This skimmer has a second chamber so almost all the CO2 should be getting used up. Now to fix this issue. I had glass tops on this tank that I have removed most of them. I have also now moved the powerheads closer to the top of the tank to agitate the surface more. Is there anything else I can do to raise the pH in the DT besides adding an airstone to it? I guess i can turn the effluent down but reduce the pH through the CaRx so the output of Alk, Ca and Mg remains the same but not as much CO2 is introduced into the tank? Skimmer is turned off and removed so I can not run an air line from outdoors to the intake or insert the effluent from CaRx into the skimmer. Im sure this is only a big issue right now as the house is so closed up and things will not be as bad when it gets to be summer and windows can be opened up.

 

[saltyfilmfolks]

Skim dry.

 

[JordanM]

Skim dry.

I removed the skimmer. It was a HOB which was hanging on the front and was only temporary so I do not want to run it any longer.

 

[saltyfilmfolks]

Are you running a single or dual stage reactor ? You’d be wise to run a dual. You’ll need to off gas somehow.

Boosting alk is not the issue.

 

[JordanM]

Are you running a single or dual stage reactor ? You’d be wise to run a dual. You’ll need to off gas somehow.

Boosting alk is not the issue.

Dual stage, GEO 612x2

 

[saltyfilmfolks]

Then yes , You’ll have to dial the co2 back and see if you can find the sweet spot that uses less co2 and maintains the alk.

 

[JordanM]

Then yes , You’ll have to dial the co2 back and see if you can find the sweet spot that uses less co2 and maintains the alk.

By this you mean slowing the effluent and raising the pH in the reactor to maintain the same dose to the tank correct? This is probably what I should do anyways since I doubt hardly any of the mag is getting into solution at pH 6.8-6.85.

 

[saltyfilmfolks]

By this you mean slowing the effluent and raising the pH in the reactor to maintain the same dose to the tank correct? This is probably what I should do anyways since I doubt hardly any of the mag is getting into solution at pH 6.8-6.85.

Yup. Just as you suggested in the original post.
Hopefully you can find a sweet spot.

 

[JordanM]

Thanks, I was surprised that my alk went up as much as it did since turning on the reactor with a decrease in the Calcium. I am going to attribute this to the few doses of Kalk i added to buffer ph. Hopefully stopping dosing now with Kalk, there will be a correlation between the Cal and Alk.

 

[JordanM]

Yup. Just as you suggested in the original post.
Hopefully you can find a sweet spot.

What would you say the slowest you would run the effluent to prevent clogging? Im using 1/4" line and running the peristaltic fxstp at 9ml/min I am getting about 1.5 drops/second.

 

[saltyfilmfolks]

What would you say the slowest you would run the effluent to prevent clogging? Im using 1/4" line and running the peristaltic fxstp at 9ml/min I am getting about 1.5 drops/second.

I’m not 100% sure that’s a big concern. But a good question.

I need more eyes. #reefsquad.

 

[ndrwater]

Personally I run a pretty steady drip/slow stream on my effluent line. No clogs that way.
There is a really good video on how to set up a CaRx using this method. I'll find it and post it.

I also run a pretty high pH in my reactor too. Mostly because of the volume of water running through. Helps to not drop the display pH to low

Found it..

 

[ndrwater]

Using the method above in my Geo 818, I was able to raise the pH in my reactor which in turn helps maintain a higher pH in the display. My tank is a 240 absolutely packed with SPS that grow like weeds. My min/Max CaRx pH is 6.9 and 6.95 respectively. My Alk is a rock solid 8.7. my skimmer is a SRO 5000 and runs 24/7. Display pH is 8.37 and runs a wonderfully consistent wave never dipping below about 8.1

 

[saltyfilmfolks]

Using the method above in my Geo 818, I was able to raise the pH in my reactor with in turn helps maintain a higher pH in the display. My tank is a 240 absolutely packed with SPS that grow like weeds. My min/Max CaRx pH is 6.9 and 6.95 respectively. My Alk is a rock solid 8.7. my skimmer is a SRO 5000 and runs 24/7. Display pH is 8.37 and runs a wonderfully consistent wave never dipping below about 8.1

Spot on. Thanks dude !

 

[JordanM]

Using the method above in my Geo 818, I was able to raise the pH in my reactor which in turn helps maintain a higher pH in the display. My tank is a 240 absolutely packed with SPS that grow like weeds. My min/Max CaRx pH is 6.9 and 6.95 respectively. My Alk is a rock solid 8.7. my skimmer is a SRO 5000 and runs 24/7. Display pH is 8.37 and runs a wonderfully consistent wave never dipping below about 8.1

This seems counter intuitive to me that a higher flow rate through the reactor but maintaining a higher ph in the reactor would keep the display pH higher. It seems that the more water you run through the reactor the pH would be more likely to be reduced to that pH.

Hence why i was thinking that a slower effluent but lower pH would lead to a higher pH in the display. So this thinking is wrong?

I also moved my Mp40 closer to the top of the water to increase surface agitation and turned the pumps up a little higher so agitation should continue throughout the night.

 

[ndrwater]

It really is relative. My somewhat high pH in the reactor doesnt affect the pH in the display due to the relatively minimal amount of flow relative to the water volume in the display/sump.
Couple that with the fact the water in the reactor doesn't become super saturated with CO2, there seems to be less of a affect on the display pH.
However you get to your desired setting for pH in the reactor, start high and work low. I was amazed when I initially set up mine with where I ended up. I was also under the assumption I needed to have a much lower pH in the reactor, but found otherwise.
Starting at a pH of 6.5 +/- will affect ALK much quicker to. Not necessarily for the good.

 

[JordanM]

It really is relative. My somewhat high pH in the reactor doesnt affect the pH in the display due to the relatively minimal amount of flow relative to the water volume in the display/sump.
Couple that with the fact the water in the reactor doesn't become super saturated with CO2, there seems to be less of a affect on the display pH.
However you get to your desired setting for pH in the reactor, start high and work low. I was amazed when I initially set up mine with where I ended up. I was also under the assumption I needed to have a much lower pH in the reactor, but found otherwise.
Starting at a pH of 6.5 +/- will affect ALK much quicker to. Not necessarily for the good.

The one thing i remeber happening when I tried running at a high flow was that my pH would go up and down in the reactor based on the pH of the tank going up and down. Yes, I can control this with the solenoid but i was trying to dial this in so the solenoid would cycle as little as possible. Do you also notice the pH go up and down more as the pH in the tank goes up and down? Also what flow rate would you guess you are currently at? 50-100ml/min?

 

[topjimmy]

Kalkwasser raises ph.

 

[Randy Holmes-Farley]

FWIW, the parameters in the first post look fine to me. [emoji3]

 

[ndrwater]

The one thing i remeber happening when I tried running at a high flow was that my pH would go up and down in the reactor based on the pH of the tank going up and down. Yes, I can control this with the solenoid but i was trying to dial this in so the solenoid would cycle as little as possible. Do you also notice the pH go up and down more as the pH in the tank goes up and down? Also what flow rate would you guess you are currently at? 50-100ml/min?

My pH is a very consistent wave. I'll post a pic in this reply.
As for my effluent flow rate, I just measured it and it's 120 ml per minute.