400 gallon SPS tank..Ca reactor can't keep up?

[Untamed12]

My 2 stage Ca reactor is 6" D x 24" tall....2nd stage is 4"D x 24" tall. The pH of the reactor is held at 6.6...and I'm flowing about 120ml/minute through it.

Yet...it's not keeping up with demand. Compared to most, I don't think my Ca demand is as high as many of the large tanks in this forum. While the tank is large, my SPS are nowhere near the size they are going to achieve in another year or so. I can see the amount of SPS that I have reaching 10x what it is now.

Alk will start the week at 8.3...but fall .2 per day unless I add bicarb every few days. Ca level remains pretty steady.

I am adding Kalk, but have hit maximum evaporation replacement. I think that increasing evaporation so that I could add more Kalk wouldn't make much difference.

Even though the pH is steady at 6.6, and 100+ ml/min is a pretty steady flow...the media doesn't really disappear very quickly.

So that is the long, necessary, background. Here are the questions:

1) What sort of flow rates and pH are other large tank people running on their reactors? (ml/min)

2) Do I just need a LARGER reactor?...or should I change my 1/4" tubing for something larger and push more water through?

3) How much can I lower the operating pH of the reactor?

 

[shaw]

You wrote that your calcium levels are pretty steady but your ALK falls.
Can you set up a dosing unit just for Bicarb?

thanks
shawn

 

[Untamed12]

<a href=showthread.php?s=&postid=12293233#post12293233 target=_blank>Originally posted</a> by shaw
You wrote that your calcium levels are pretty steady but your ALK falls.
Can you set up a dosing unit just for Bicarb?

thanks
shawn

Yes...it may come to that....but I think that Randy H-F would probably tell me that falling Alk likely means that I'm not adding enough balanced replenishment. One just sees the weakness in the Alk earlier.

 

[polywise]

Untamed12,
I have 500 gallons in my system, and my reactor is set at .50ml, and 6.5 ph in the reactor. system preasure in the reactor is about 7.5 psi. do you have a recirulating pump on your reactor?
three things:
First: what is your MG level? because that helps support ca, kh,and alk
Second: is your PH being monitored in the reactor chamber, and calibrated recently?
Third: I think that you need to back off on the flow a bunch- to allow the PH to actually work on the media (contact time).
just my opinions

 

[Untamed12]

Mg is good. It's never been under 1300 whenever I test it.

It has been a few months since I recalibrated the reactor probe. I'll do that again. No harm.

Yes, the reactor has recirc pump. The reactor is a PM620.

When you say .50ml...you mean that you flow the reactor at 50ml per minute?

I can't measure the pressure of the reactor.

I would think that if the flow through the reactor was so great that there was no reaction time....that the pH of the reactor would start to equal the pH of the tank. As is, the CO2 frequently shuts off because the pH of 6.6 is stable.

I think I'll drop the reactor to pH 6.55...then maybe to 6.5...trying to dissolve media quicker.

 

[cweder]

You can also measure the Kh of your effluent. This will tell you if your getting the most out of it. By slowing down the effluent it should give you a more concentrated Kh and overall better able to keep up with demand.

 

[Plato]

You may be pushing to much through the reactor, 120 ml min is a lot. Polywise ask the main ? about Mg, go for a minum of 1350 to 1500, very important to calcium suplimentation. Use a good Kh test kit, I recomend salifer to test the efluient leve. Take a measurement now and write down. Dial back the reactor to 5 ml min with a clean and freshly calibrated pH brobe. Run the reactor for 24 hours then remeasure kh write down should be aprox 20 dkh. Now measure Ca and Mg, start to rase efluent to 10 ml min for 24 hr, then remeasur kh (both tank and reactor), Ca, and Mg. Next sucessive times increase by 20 ml min per 24 hours. The main idea is to make sure if the reactor can provide efulent Kh of 20 Kh at 5 ml min then at say 100 ml min you should also have an efluent Kh of 20 kh. I just refiled my Ca reactor last week, cleaned, and calibrated the probe. I use MTC ProCal, it has a glass flow meter so I know exactly how much I am dosing. It is controled by a pinpoint controler, using carib sea ARM and is running at 2-3 psi. When I first start it up I find by running the above break in procedure, my reactor is up to full running capicity in just a few days. My tank is 275 gall reef mix sps mainly. The most I ever run the ProCal is 30 ml min. Befor I used this break in process it would take days and even a week to come on line. The above process will also let you know the maximum limits of your calcium reactor.

 

[Untamed12]

That's good advice. Reactor is fed by a dosing pump, and has been running for over a year. I've just been slowing increasing the flow through as my Ca/Alk demand increased until I began to think...this just can't be right!....

I've not been measuring the Alk of the output. I'll do that and see if I'm close to 20. Then I'll start playing with the flow through rates and see what happens at what levels.

 

[jjjimmy]

I think that you went the wrong direction with your effluent rate. You should have slowed it down instead of increasing it. You need to get more reaction time of the low Ph water with the media. You stated yourself that the media is not dissapearing quickly. That alone should tell you that you are not giving the reactor enough reaction time to do what it needs to do.

 

[smcooler]

same prob. for me running a pro-cal on 300 gal sps reef cant keep up, have to dose 230 mills of part a and 200 mills part b of esv b-ionic to keep dkh at 9.5 and ca. at 400.


stan

 

[polywise]

Untamed12,
Correction to my post -- I just checked the flow meter on my MTC pro-cal reactor, and the ball is at .05 l/min = 50 ml/min

 

[smcooler]

<a href=showthread.php?s=&postid=12297413#post12297413 target=_blank>Originally posted</a> by polywise
Untamed12,
Correction to my post -- I just checked the flow meter on my MTC pro-cal reactor, and the ball is at .05 l/min = 50 ml/min

what media are you using in the pro-cal and whats your bubble count are you fully stocked with sps?


s

 

[polywise]

smcooler,
I am using ARM

2 bubbles/second -- using a ph CONTROLER contorller, not a MONITOR.
+-22 pcs SPS mostly small 2-5" -but, one hydnrophora aobut 8"
3 montipoa
4 lps -

 

[smcooler]

Jim C. thanks for the info.


s

 

[Plato]

Untamed12 don't hit me. I told you wrong earler. I am in front of my tank now. When I origonaly said to break in at 5 ml min that shoud be 20 ml min. The glass flow meter has a .05 mark for H20 which I remember means 50 ml min. That is what it is set at now, I am getting 24 dKh out of the reactor, Ca is 100 ppm above what the tank reads. I was running it at 100ml min for the past weed to get cought up, now it is a 50ml min. My tank is a 275 with some big corals sps and lps however it is not a full as say the tank of the month. I have something like 40-50 fish in the tank. Most are angels, big angels.

One other thing my tanks Ca and dKh have been rising for the past few days but today they both fell mainly due to Mg falling below 1300. I find that keeping the Mg between 1350-1450 helps both levels and the evidence is greatly demonstrated in my montopora cap, just in past few weeks of getting the reactor back on line, their is a 1/4 growth ring that has apeared in the past two weeks. The whole coral is 18" long x 12" wide x 13" tall. It is all one massive top plate and it loves my reactor.

smcooler what are you Mg leves. The procal can pump out up to 300 ml min. I have run mine at 200 befor in the past when the tank was first set up, but I still got 20-25 dkh out of the reactor, it however consums the CO2 at that point. Check you Mg levels and effluent reactors Dkh from the main reactor. I have a ball valve in line on the CO2 gass off line or red line that is contriled by the flote in the ca reactor. It wast to much gas. My reactro usually has a 1-2 in layer or CO2 gas all of the time when I run at extream rates 150ml min or more and just .5-1 inch at 50-100ml min. But I always get abot 20 dkh from the reactor.

 

[Untamed12]

We are closing in on the problem...I measured the output Alk and it is.....13dKH!!!

So I have dropped the pH of the reactor slightly...and slowed the flow. We'll take another measurement tomorrow.

 

[smcooler]

smcooler what are you Mg leves. The procal can pump out up to 300 ml min. I have run mine at 200 befor in the past when the tank was first set up, but I still got 20-25 dkh out of the reactor, it however consums the CO2 at that point. Check you Mg levels and effluent reactors Dkh from the main reactor. I have a ball valve in line on the CO2 gass off line or red line that is contriled by the flote in the ca reactor. It wast to much gas. My reactro usually has a 1-2 in layer or CO2 gas all of the time when I run at extream rates 150ml min or more and just .5-1 inch at 50-100ml min. But I always get abot 20 dkh from the reactor.


__________________
I also run the reactor to the extream, there is a few inchs of turbulent co2 at the top and the drip rate is just not a steady stream, if that makes sence. The media needs to be replaced at a bout 3 months or less.


s

 

[Plato]

hey yall. just wanted to chime back in. I was at on of my friends tanks today, he has a 180 runing a MRC CR-4 reactor with spraybar option. His flow rate measured at 13 ml min but the dkh (salifert) was 42, and he has some great sps.