Calcium reactor effluent dialing in?

[TLO45]

I have a 375 gallon display with 90% sps. I’ve been running a newer Geo Super Silent calcium reactor with 818 main chamber followed by a second 618 chamber. Running Reborn larger grain media in 1st chamber and Reborn finer media in second chamber. Carbon doser regulator and Milwaukee ph controller.
Here’s my question. I know this is basic calcium reactor 101 info but I’m having a hard time dialing in the Alk.
As the coral has been growing I’ve needed more alkalinity. According to Geo I should DECREASE the effluent rate so the water has more time to contact media thus increasing potency. As I continued to lower the flow rate the alkalinity continued to DROP!
So to avoid a total disaster I INCREASED the effluent rate and that stopped the falling Alk numbers but now I’m having a hard time getting Alk to raise back up.
After doing more reading (as I understand it) if I increase the effluent rate I also need to increase bubble rate? I have the ph controller set at 6.5 currently which I also understand shouldn’t go much lower due to melting media too fast? I also increased the bubble rate on the ph controller to approximately 2 bubbles per second? Does that sound right?
I’m currently running the versa pump which feeds the calcium reactor at 65ml per minute which after reading articles seems high.
I’m a bit nervous to continue adjusting ph, effluent rate bubbles per second ect because my Alk this morning was 7.1. It was 9.0 about 10 days ago and up from 6.7 a few days ago. I don’t want to have the Alk continue to bounce around and start loosing coral.
It sounds like those running calcium reactors have their effluent rate set much lower. I’m wonder if my system actually draws that much ( yes I have a lot of sps) or if I have the reactor set up completely wrong?
I’ll include pictures of the mobius read out to clarify.

 

[TLO45]

 

[X-37B]

I dont use a controller or ph probe so I cant comment on that method.
How much alk does your system use in 24hrs?
You use a basic 2 part, I use esv, to get alk/ca to where you want it.
Dont try to raise by adjusting the reactor.
You will be dosing 2 part daily to keep alk stable until the reactor takes over.
So I set my co2 to 1bpm, example. I then adjust my Kamoer to 40ml per minute as an example. Measure effluent alk after 24hrs. You want 20-25 alk in your effluent. Adjust bpm and effluent until you see the 20-25.
Adjust alk daily with 2 part to keep it at your desired alk.
I pull effluent through the reactor with a Kamoer pump.
I will be setting my 818 up as soon as demand is there.

So once you have your alk stable, say 8 for example, and the reactor is holding it you are set. When demand goes up you adjust both bpm and effluent rate upward together in the same ratio.

I have never run a controller but the basics still apply.
Set bpm and effluent to get to 20-25dkh. Someone can explain the controller ph part but for me its just another piece of equipment I dont need.
My soon to be running 818.

 

[TLO45]

Not sure what my exact effluent Alk number is because I test with a Hanna checker. However the test result is flashing 20 and vial is blue so I can only assume is above 20. How much above I do not know.

 

[Kzang]

Not sure what my exact effluent Alk number is because I test with a Hanna checker. However the test result is flashing 20 and vial is blue so I can only assume is above 20. How much above I do not know.

The way you can do is is take a 2.5ml of reactor effluent, and put 7.5 of rodi. Get the number and times it by 4 and you’ll get your alk.

 

[TLO45]

Using that method effluent is 31.2

 

[TLO45]

Ok I believe I have finally understood how this works!
Thanks for the thorough explanation!

 

[cilyjr]

The way you can do is is take a 2.5ml of reactor effluent, and put 7.5 of rodi. Get the number and times it by 4 and you’ll get your alk.

I like this.
Can I assume using a salaifert kit that requires 4 ml of testing solution. You go 1 to 3 with effluent to rodi?

 

[Kzang]

I like this.
Can I assume using a salaifert kit that requires 4 ml of testing solution. You go 1 to 3 with effluent to rodi?

Whatever method you choose, just take 1/4 or 1/2 effluent to rodi.

I like 1/4 just because 1/2 might be too high and waste a test.

Correct. So if you use 4ml, you’d use 1ml effluent to 3 ml of rodi.

 

[cilyjr]

Whatever method you choose, just take 1/4 or 1/2 effluent to rodi.

I like 1/4 just because 1/2 might be too high and waste a test.

Correct. So if you use 4ml, you’d use 1ml effluent to 3 ml of rodi.

Thanks for this. Very helpful

 

[helmsreef]

If your effluent is at a good Alk level and you want to increase your output for your demand you can increase effluent flow and decrease your minutes per bubble (if you are using the carbon doser). I use the same setup with Geo and secondary chamber with just the course media in both chambers. Every month or so due to demand I will decrease minutes per bubble and increase flow rate to make sure my ph stays stable and the controller is not continuing to be shut off and on by my apex. My effluent is 26dkh and I will try to maintain that number to be able to make my calculations. My system has been at 8.3-8.4 for months now with very little flucuation.

 

[Jason_MrFrags]

Do you know if your co2 ever shuts off?
How fast is the effluent flow?

 

[TLO45]

Problem has been solved!
I want to clarify that the issue was NOT THE GEO REACTOR but rather the Versa pump I was using.
After contacting Geo personally (Alk was not adjusting in the display as I had hoped) they mentioned that the effluent rate didn’t appear to be as strong as I had it set for. I dug in deeper to find the Ecotech Versa pump needed replacement! I had replaced this tubing one month ago but it had flattened enough to affect the dosing amount. I replaced it last night and this morning Alk in the display was 8.4!
I appreciate everyone’s input especially Geo Staff for sticking with me and helping me through this!
Much appreciated!!!

 

[teaktoc]

For those with DKH around 25 in effluent direct to tank, what is the effluent PH that is going direct to tank?