Out with the old! In with the new!

[JSB]

Out with the old:

In with the new:

So I have pulled off my 2+1 part dosers and stepped up to a calcium reactor. I have the bubble count set to 1-per second and the effluent to 4oz/minute per the mfr. I want to dial in the ph probe and controller, so should I target 6.5-6.7 in the reactor? Then leave the effluent alone and keep reading calc/alk and then adjust effluent accordingly?

H@rry? Tomoko? Anyone?... Bueller? Bueller?... Hey is this thing on?

 

[JSB]

Ok, so my tank pH is plummeting, but I guess this is to be expected to a degree. It is down to 7.7, and that concerns me. I set up the CO2 regulator to turn ON as long as the pH in the reactor is greater than 6.6, and to turn OFF if the tank pH is less than 7.8 as a fail safe. With this setup, will I be able to get enough Ca/Alk into the tank?

Should I instead of turning off the regulator, reduce the effluent?

 

[H@rry]

Don't worry about the tank pH. 7.7 is about where mine is (or was last time I checked). I simply have my controller turn the CO2 on when the CARx pH goes above 6.7 and otherwise off.

I'm not sure how much 4oz/min is but I have mine wide open - a pretty good steady stream. I never bother the effluent rate, I just tweak the CARx pH to raise or lower the alk.

I'm trying to look at your pic and understand what I'm seeing. What is at the two ends of the longer gray tube on the right? There's something with a blue band at the bottom and something else on the top.

 

[JSB]

Well, my tank is about third of yours, and not as stoney, so I have dialed it back to 60 drips a minute, and pH is still low (7.85) but not diving any longer. I set up my CO2 like yours, and have tested the alk at around 10dKh. I will check it again tomorrow and see which way to dial it up or down. Thanks and wish me luck.

 

[H@rry]

It's really got very little to do with the tank size. You adjust the CARx to maintain the alk you want. Assuming the same size reactor, a bigger tank will take a lower pH to maintain a constant alk while a smaller tank will need less. I run the frag tank the same way at the 480 gallon system. The CARx on the big system is larger than the one on the frag tank and I'm running that one at 6.7 and the frag tank at 6.9. With a new charge of media in the one on the frag tank I might only need to run it at 7.1.

BTW, if you just set it up today and the alk is already at 10 you might want to shut it down until you can get it calibrated better. If it runs all night like that no telling what it will be in the morning.

 

[JSB]

Ah! So I might want to open the effluent back up, and run the CARx pH up to 7.0 and go from there?

 

[H@rry]

Ah! So I might want to open the effluent back up, and run the CARx pH up to 7.0 and go from there?

That sounds like a better approach, expecially until you get the "feel" of how your system and reactor are working with each other and how it responds to changes you make.

 

[JSB]

Ok, I have the effluent cranked back to the 4 ounces a minute rate, 1 bubble a second CO2, and a 1 bubble a second rate on the recirc pump, I have set the regulator ON at 7.1 and OFF at 7.0. I put the low end cut off in there because 1 bubble a second will drive the CARx to 6.5 in a heartbeat, and the needle valve on the solenoid is so sensitive it is hard to dial down much further without turning it off. This will be my base configuration and from here I will only adjust pH in the reactor itself. Sound about right?

 

[H@rry]

OK now, tell me about the 1 bubble a second rate on the recirc pump. The pump runs wide open all the time. I don't understand what you mean by that.

I think part of the problem is trying to count bubbles. Let the controller handle the CO2 solenoid and forget about bubbles. Just barely crack the needle valve and watch the display on the controller. If it can't allow enough CO2 in, crack it just another "1/2 hair". The way I adjust the needle valve is squeeze it pretty hard and barely put a little torque on it. When you have moved it just right, you won't be really sure you moved it at all. If you feel it move very much, that's way too much.

You also have a .1 gap between on and off. Mine is just a true/false test. pH > 6.7 = on || pH < 6.7 = off. The problem is that you are opening the CO2 solenoid when the pH >= 7.1 and holding it open until it <= 7.0. This is resulting in the CO2 "flooding" the chamber before some of it comes in contact with the probe. By the time the probe picks it up, there has been so much allowed in that even though you closed the solenoid it continues to drive the pH down.

 

[JSB]

OK now, tell me about the 1 bubble a second rate on the recirc pump. The pump runs wide open all the time. I don't understand what you mean by that.

The installation manual said let the CO2 head build up, shut off the solenoid, and adjust the recirc pump (via the recirc valve) to push the CO2 head out at the same 1 bubble a second rate. During the tuning, it quickly exhausts the CO2 head then is just pushing water, but that is what they said to do to calibrate the recirc.

You also have a .1 gap between on and off. Mine is just a true/false test. pH > 6.7 = on || pH < 6.7 = off. The problem is that you are opening the CO2 solenoid when the pH >= 7.1 and holding it open until it <= 7.0. This is resulting in the CO2 "flooding" the chamber before some of it comes in contact with the probe. By the time the probe picks it up, there has been so much allowed in that even though you closed the solenoid it continues to drive the pH down.

Well, looking back at my code, it truly is >7.1 ON and < 7.1 OFF. The way I had it written would never evaluate the < 7.0 test.

I am concerned with the solenoid going into hysteresis and clicking on and off every few seconds, so a slower bubble rate is probably going to be required. It could disturb my slumber on the couch nearby.

 

[H@rry]

Well, yours is a little bit more sophisticated than mine. I don't have a valve on my pumps. My recirc and feed pumps run wide open all the time.

 

[hawkinsrgk]

Why did you decide to stop using 2 Part?

 

[JSB]

Why did you decide to stop using 2 Part?

I have spent the last year chasing Alk and Ca (Mag not so much). Every week it is something. Too much of this, not enough of that. With a controller, it was doable, but it was not optimum. On the advice of many, H@rry included, I was swayed by the apparent ease of use of a CaRx. I know it will take me a couple weeks of fine tuning to get it dialed in, but with the dosing pumps, it was constant. Virtually every week, I had to make adjustments. That, plus the hassle of mixing up the 2-parts, it just seemed like the path I wanted to go down.

 

[H@rry]

What are your numbers like this morning?

 

[JSB]

What are your numbers like this morning?

Alk is up to 10.6 from 10.1, but I tested it yesterday before I finished the tweaking. 10.6 is now my baseline going into tomorrow as I don't plan on any more changes today. I have the CO2 feed where it is pretty stable at 7.05 in the CaRx without chattering the solenoid every few minutes. pH in the display is 7.93 and was stable there over night.

If I find that this is the right dose, I will let Alk drift down to around 8.5 to 9 and resume with the reactor.

 

[H@rry]

Right on! That sounds exactly right.

 

[JSB]

Ok, this morning's readings look pretty good. 195ppm (10.92 dKh) compared to yesterday's of 191 ppm (10.68 dKh). Tank pH this morning is 7.92. I might assume the alk reading delta could be the margin of error in the test kit (Hanna), but I am going to take it as literal. I had the solenoid cycling on at 7.7 and off at 7.2 to minimize the swings and the chatter. I am going to move that range to 7.07-7.1 and see how tomorrow goes.

I have them surrounded...

 

[JSB]

My Alk this morning was 196ppm (10.97dKh), up 1ppm from yesterday, and that, for now, will be attributable to the margin of error in my testing. Ca is 427ppm, which is about right. pH in the tank is pretty stable between 7.92 (night) and 8.04 (day). I am going to turn off the CaRx for a bit and let Alk drift back down into the 8-9 range, dose the Ca back up if necessary, and then resume with the CaRx again. Then I am going to sit back in my chair and listen to the reassuring clicking of that solenoid valve...

Actually, I am going to start planning a solenoid valve muffle! Thanks for your help, H@rry.

 

[H@rry]

I am going to start planning a solenoid valve muffle! Thanks for your help, H@rry.

When you get that figured out hollar at me.

 

[pickupman66]

Can't stand the click huh? Glad you are getting it dialed in. I love me reactor. And trust me, once dialed it they keep the tank rock steady. Just don't forget to keep up with increased demand from growing corals.

I also use a controller setup. Set to 6.8 in my chamber and I could carenless about bubble count. Effluent is a steady stream just past a drip.

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