dKH oh my!

[ieatchinese]

Our tank is doing ok, but we have had a battle with alkalinity (dKh). Very shorthly after I installed our new Precision Marine calcium reactor our dKh was 12. The problem is, it kept going up. Calcium was 420 for a while, but started to drop as dKh went higher. We topped out at dKh of 20 and calcium of 380. Friends told us to get the dKh down. I have turned off the reactor for two weeks now and it is finally getting to 9 dKh. We hovered in the range of 12 dKh for about a week. Calcium is now at 420 and dKh is 9.

When we identified all of this, we were also told that magnesium might be our problem. So....we got the magnesium test kit and if we are doing it right, we measured 1140. We began dosing magnesium and slowly it has come up to 1300. dKh has leveled off at 9 as stated above, but issue is:

I now want to start up the reactor again, but I dont want to fight this battle again. My reactor was originally setup following the instructions that came with it and it is now simply dripping with no CO2 (this is how I turned it off....disabled the CO2). We had put some "UltraMag" in the reactor 2 weeks ago, but within the day, dKh was on the rise again, thus the reason that I effectively turned it off.

I saw a thread a while back about calcium reactors that indicated two schools of thought....

Classroom #1:
you can't use a reactor to change the calcium and alkalinity in your system...only to maintain the current levels

Classroom #2:
You can use a reactor to change the calcium and alkalinity in your system and when it gets to the point that you want, dial it in to maintain it.

I had subscribed to classroom #2 above and my dKh skyrocketed...even though I was dialing it in constantly. I had dripping at a rate that was barely noticeable. I had also ran it full out, thinking that there was much less time for desolving the media. Both approaches didn't seem to work. The slow drip clogged the valve about every two days or so and the full flow simply kept raising the dKh.

I also changed the pH trip points of the effluent. I originally set it up to the recommended levels from the reactor instructions (CO2 - ON @ pH 6.7, CO2 - OFF @ pH 7.0). I raised this range over a 1 month period, ending at CO2 - ON @ pH 7.8, CO2 - OFF @ pH 8.0 and the dKh simply kept rising.

As I said, the tank is where it should be now, but I don't want to go through this headache again....any suggestions?

[kimoy]

i think that you need to lower the pH settings on your monitor.

[ieatchinese]

kimoy,

Your message is a little confusing. I realize that my reactor needs to be 6.7 to 7.0 in order for the media to disolve and that is the way that it was originally set up. When I started to have problems, I raised the setpoints and the problem continued. I finally got to the following setpoints and gave up and simply shut off my CO2 and opened the valve so that water was runninng through the reactor (I didn't want to have stagnant water in the reactor. The dKh is now in range and I am contemplating turning on the CO2 again....and I will go to the original setpoints of 6.7 to 7.0 when I do.

Are you suggesting that I lower the setpoints even more?

[jim.l]

If your calcium and alkalinity are going out of balance only because of your reactor, the problem is your media. Quality crushed coral is a lot cheaper than manufactured "reactor media" and it's balanced. It has cal/ alk/ mag, and all the trace elements that corals need in the proportion that corals utilize them.

[ieatchinese]

jim.l,

Thanks. I just followed the reactor manufacturer's recommendation and used the A.R.M media. I will try crushed coral.

[ppurcell]

generally speaking your reactor should be used to maintain a particular alkalinity. If you use it to raise your alkalinity, (Eg. add more alkalinity than your animals are using) then that will continue until the tanks alkalinity is outside of acceptable parameters.

If you are seeing that your alkalinity is rising when you test, you can do one of three things. Raise the pH in your reactor, reduce the effluent drip rate into your tank or both if the rate that alkalinity is increasing very fast.

Keep in mind that depending on where you are measuring the pH of your reactor (primary chamber, 2nd chamber or effluent) it may take a substantial amount of time before any changes made on the CO2 delivery rate register on you pH controller.

[Flint&Eric]

your media is fine...i agree with ppurcell

[Sullyman]

A calcium reactor dissolves media by the addition of co2, the media releases calcium and carbonate, thus adding them to the tank. You control how much is added by setting the CO2 and effluent drip rate.
What are you measuring, tank water or effluent? If it's tank water, no good, if it's the effluent then it may not be bad.
The effluent(the water coming out of the reactor) should be high in calcium and carbonate, higher than you want in the tank.
I'm not sure about the last part, CO2 on at 7.8 off at 8.0, the co2 should go on when the Ph rises above the recomended level for the media you're using and go off once that level has been reached.
You are trying to do this without a Ph controler?

[ieatchinese]

I am measuring alkalinity and calcium with water from the tank, not the effluent. I have a Aquacontroller III and have it set to turn off and on the CO2. The 7.8 to 8.0 was as I described in my original post, a point to which I adjusted the setpoints in order to control the excessive alkalinity....but to no avail. My original setpoints were 6.7 to 7.0. this worked, but so well that my dKh was hitting 18 to 20. I bumpted the setpoints in the AQIII control program up incrementally into the 7.1 to 7.5 range with the understanding that there would be little or no media desolved, thus lowering the alkalinity. Didn't work and therefore I went all the way to 7.8 to 8.0 for the setpoints (CO2 off and CO2 on respectively). This still didn't result in a drop of the alkalinity over a two week period. I therefore simply turned off the CO2 for the past three weeks. dKh is now 8 and calcium is at 400. Started the reactor up today....will monitor and see if levels are maintained or they skyrocket. Setpoints for the CO2 in the program are set to 6.5 and 6.9.

[Sullyman]

Where is the Ph probe? In the tank? If that's the case it could be your problem.

[cas]

People have been reporting melting mushrooms and it turned out that their alk was really high from a bad batch of RC salt.

Next time you do a water change you may want to test before adding to the tank.

[Sullyman]

I've used 15-20 buckets of RC in the last year, no problems.
IEC, do you understand what I said? If the probe is in the tank or an overflow, or even a sump, you won't be controling the co2 correctly. How often is the co2 going on and off, should be doing that every 15 to 20 minutes. If you've got co2 feeding the reactor based on the Ph of the tank, this would explain what's going on.
You may have really saturated your media with co2.

[hoosierpat]

Set me straight if I'm wrong, but won't CO2 lower the pH of the tank. If so, you have the controller set wrong. The pH should be set to turn the reactor off when it gets too low and the highpoint should be your on. I don't think that's your problem and I may be totally wrong(I'm going to look it up in a book right now)but that may have something to do with it.

[hoosierpat]

Actually, that is definitely right. That is why you leave your refugium light on for 24 hours. It reduces the free carbon dioxide in the tank, therefore, maintaining a higher pH during the night when pH usually drops due to an excess of CO2 in the tank because the algae is not performing photosynthesis.

You may have typed it wrong but from your first post, your gas should be on at 7.0 and off at 6.7.

[ieatchinese]

Sullyman:
I have two pH probes and one is in the tank and the other is in the effluent output. I am sure some people make such mistakes, but I don't.

Hoosierpat:
My setpoints are to turn OFF my CO2 when the pH of the effluent gets down to 6.5 and turn it back on when the effluent gets to 6.9. I know what I am doing here and you are right, CO2 added to the water will lower the pH.

[ieatchinese]

hooseirpat:
You are right, I typed it incorrectly in that part of my first post. Sorry for any confusion caused.

[madadi]

maybe you should try to recalibrate your probes?

i drilled a hole in the top of my PM calcium reactor and i inserted a pH probe directly into the first chamber. i feel like im able to better control the pH inside and the CO2 tank is not on as much as it was when i had it testing the effluent coming out of the reactor.
premiumaquatics.com and marinedepot.com have the probe holders that you can use to mount your probe inside the reactor. i can post pics if your interested. i didn't have your problem but it sure made it easier to control and monitor.

[ieatchinese]

madadi,

Thank you! I have thought about doing this many times. Actually, I thought that it had this feature when I bought it, but it turned out that the model I got didn't have it. It was the next larger model that has this feature. It would be great if you could post the pics.

Thanks,
Roy

[Sullyman]

Roy, I'm just trying to help figure out why you're having issues with your reactor, not trying to catch you in a mistake.
How are you reading the effluent Ph?
Do you see the co2 kick on and off, or hear the solonoid clicking?
Roy another thought, if you've got the Ph set points at off at 6.5 and on at 6.9 and the co2 isn't running fast enough, it could be on long periods and cause the issues.

[madadi]

adding the probe holder was surprisingly easy. it took me about 10min and just a couple of hours curring time. i have the PM 422 calcium reactor so the only issue was to find the perfect spot where to drill the hole because i didn't have a whole lot of space to work with.



here is the top of the reactor removed so i can drill it



tool i used to drill the hole, use any hand drill. you can see what the probe holder looks like unmounted. bought it from premiumaquatics.com what you have to remember is that the top of the calcium reactor is 1/4in acrylic and the probe holders thread is not that long so i just used twopart glue to attach it to the top.












when i first got my calcium reactor it took me a while till i got it all worked out so don't get discouraged. i use the ARM course media. with a pH of 6.7-6.9 maintained it pretty well but i don't have many corals, just frags.

do you have the water coming trough the bottom and out the top? like that the pH wont be stuck inside the reactor and dissolve the media too much. use an aqua lifter pump to draw water out of the top and into the sump. its 10 bucks. you regulate the flow with the valve at the top of the reactor. it hold a really slow flow of one or less drops per second without it clogging up. good luck!

[ieatchinese]

madadi,

Thank you very much! I will do this as soon as I get the parts. My reactor is the RFCa4 and therefore the flow is a little different than yours. I kind of like your suggestion to use an aqualifter pump. I may try that. I am currently feeding the reactor from my sump with a maxijet 1200.

Thanks again!
Roy

[ieatchinese]

Sullyman,

No worries, I understand and I know that you are trying to help. The problem is, I have already moved on past much of this and now I am beginning again. The scenario is this...

I had the problem of high dKh and then shut down the reactor. I let the tank stabilize and when it got to dKh of 8, I started the reactor again (day before yesterday). I have my setpoints at 6.5 and 6.9 on the reactor. The solenoid clicks on and off as perscribed and bubbles of CO2 go through the bubble counter. Funny thing is, this also started happening when I switched to reefcrystals. I have stayed with this salt and maybe I was just one of the unfortunate people to get a bad bucket. My dkH is now at 10 and my calcium is at 440. I am monitoring it each day to see what happens.

Thanks for the support.

[Sullyman]

Good, just what to help if I can. Sounds like you've got it, if those levels stabalize.

[hoosierpat]

I have had about 4 confirmed cases of Reef Crystals having too high of an alkalinity. I think this is where you're problem is coming from. Mix some water and test it to find out.