calcium reactor and drip rate

[clk2609]

have a KnopC reactor on a 110g tank, just started SPS in Oct.

Question: what would the difference be if the drip rate were raised?

Example, from 40 drops to 400 drops and raising the CO2 accordingly.
Wouldn't this indeed raise the calcium because more effluent is being let out, thus also raising alk and probably decreasing pH?

I use to dose B-ionic and now still do, but not near as much. My Ca is running at 375ppm and would like it to run in 400ppm range. I will probably use Turbo Ca to raise it then adjust Knop accordingly.

Another question:

I know the effluent should be around 6.5-6.8pH....what should the alk and calcium of the effluent read?

I want to get the most out of my reactor and just wanted some opinions.

thanks

in picture, i have the effluent dripping into small blue container at bottom with pH probe inside effluent chamber

 

[Jeff Hood]

Question: what would the difference be if the drip rate were raised?

Example, from 40 drops to 400 drops and raising the CO2 accordingly.
Wouldn't this indeed raise the calcium because more effluent is being let out, thus also raising alk and probably decreasing pH?

Well, Yes but only to a point. The problem lies in the starting size of your reactor and the diminished contact time the water has to react with the aragonite and the amount of time it takes for the Co2 bubbles to disolve into the incoming water. You can imagine that if you had a small reactor running 500 cc per min through it and a continous stream of Co2 going in that you would probably have Co2 gas leaving the unit undisolved.

I had exactly that same problem trying to keep up with a 500 gallon tank with a total water volume of 800 gallons.

Here was my solution to the upper limet problem. I looked at my Small Lifereef reactor and saw most people running them at a certain rate and bubble count. I looked at how much Co2 I was using and started turning it up and also increased the flow through the unit. I found that if I went too much it became almost impossible to keep the pH down before the Co2 would just leave the top of the reactor. I essentially reached the limet of the reactors ability to deal with all the co2 coming in.

So I needed a larger reactor to handle the large effluient rate needed to keep up with my tank volume. I needed a total internal volume about 10 times what I had so the turnover of the reactor would be essentially the same as my smaller unit. I would be running 10 times the effulent rate and Co2 rate but the contact time with the reactor media would be the same as my small unit and I waist very little of the Co2 I pour in. I am now running around 150 cc per min and that is all the little pump can do for now. I feel my system has plenty of reserve left in it so when the SPS get much bigger I can increase the output. I have the little pump wide open and it is a steady stream into my refugium. My Co2 rate is difficult to count because of the variable size of the bubbles. The pH of the efluient is 6.7 ( out of the third chamber) and the Alk leaving the unit is over 28 DKH but I have not measured in a while( waist of test media IMO). I am using Koralith media. I have heard you get much higher alk readings with ARM and I am going to try it when My needs go up later this year. The important thing is my media is disolving and my Alk and Calcium reading are very stable. About an inch from each of the three chambers every few months.

Dimentions of my reactor are 6" x 36" twin tower running in parallel with a Eheim pump and a 5" x 12" third chamber running in series to catch any unused Co2.

I also run a Kalk reactor and use about a cup to two cups of kalk per week.

My Calcium runs 440 and my alk runs 11.5. pH of the tank runs 8.35 day and 8.28 at night.

I would try turning up your reactor until you are unable to keep Co2 gas from collecting and escaping out and or you are not able to keep the pH down where you need it and then back off a little and see what happens.

Good luck!

 

[clk2609]

thanks jeff for the advice. very informative. sounds like you have a pretty amazing calc reactor running.

i do understand the contact time...but how do i know if i am burning off excess CO2. My set-up right now has my pH controller turning off my CO2 when the effluent is below pH6.5 and turns CO2 when pH goes above 6.6

if i turn up the effluent flow and of course the CO2 and my pH stays around 6.6...wouldn't that mean the CO2 is breaking down the media in my chamber and i am not expellling CO2?????? Please answer this if you can.

i was running more than a drip....more like a flow of effluent out into a small container and of course my CO2 was probably running about 3 bubbles per SECOND or so. pH would go down, shut off the CO2 and then as the effluent kept running, the container effluent pH would rise above 6.6 and turn on the CO2.....just a cycle but since this really stayed on more than i wanted....my pH in tank would get depressed....around 7.8 mid day. The alk of the effluent was only about 12dKH....probably not enough contact time....like you said

so another question: i know your effluent alk is 28!!!! wow! what should the effluent calcium be?

also, do you dose kalk to maintain pH or keep it towards the 8.3?

sorry this is so long...hope you can help

 

[Garry thomas]

i'v a 4001 korallin reactor, they recommend 25to 3o bubs a minute of co2, but at that rate i was'nt reaching the required return KH. i know turning the return water flow down would help but its on a 500gal+ system so, i turned the co2 up ,
i'v now got 70 bubs a minute co 2 and a return of around 90 drops a minute. The kh is now 11 in tank which equates to an alk of 4.2 the return wter is 35+kh..............so i hope this answers your question :roll:

 

[MiNdErAsR]

My set-up right now has my pH controller turning off my CO2 when the effluent is below pH6.5 and turns CO2 when pH goes above 6.6

This could be part of your problem. Why use a controller when you can adjust the CO2 feed to run at a steady rate at the desired pH level? When you cycle the CO2, you're introducing a slug of water to the reactor without the ability to disolve media. When your CO2 turns back on it takes time for the lower pH water to begin disolving media.

You don't mention your current reactor settings, but if it's failing to maintain your desired alk and Ca levels, then it seems to me you don't have the reactor dialed in correctly. Might be time to do so. For example, if you're running 40 ml/min @ 6.5 pH, try increasing the flow rate to 50ml/min without changing the CO2 feed. Effluent pH should increase, and this is fine for now. Measure tank alk prior to any changes, then again 24 hours after changes. Should alk drop, then increase CO2 a tad and measure tank alk again in 24 hours. Continue in this fashion until your achieve stable alkalinity at your desired level.

HTH, IMO

 

[Jeff Hood]

clk2609


My alk leaving the unit is 28 dkh and that seems good but I have heard of much higher, like in the 40s. I wonder if ARM would give higher numbers? I had used ARM on my 75 for a very short period and I saw alk readings of over 21 in the main tank.
I do run Kalk via a Nilsen reactor to keep the pH up where I want it.

I think you should try running yours with out the controller and see if everything stabilizes. Running the co2 continously would be better IMO.

I agree, as long as you don't have raw co2 leaving your system and the pH stays down where you want it then you can have as fast a flow as you want to a point as stated before. As long as the alk leaving your unit is where you want it, its ok.

Now remember, 100 ml per min with an alk of 20 dkh is the same for your tank as 50 ml per min at an alk of 40 dkh, if my chemestry is correct. Just be carefull not to drop the pH so much as to turn your media to mush.

I measured the calcium in the effulient and it came out to 550 ppm. Not as high as I thought it would be.

Jeff

 

[clk2609]

i really do thank everybody with the advice. I am going to just run the effluent without the pH controller for 24 hours and measure the effluent and tank: alk, pH, Ca and go from there.

Do most of you that run a reactor use a pH controller to turn off your CO2 or do you just let your reactor run continually? and monitor.

thanks

 

[Anonymous]

I wouldnt ever let a controller mess with the co2 going into a reactor, I prefer to ballance the reactor to the tank load, with steady co2/effluent, and I monitor the effluent & tank dkh to match load. I have an octopus, but I dont monitor the reactor ph, I monitor the tank ph, and even that, is just a FYI, I dont do anything with the readings.

I use dwyer flowmeters for both co2 & effluent, counting drips/bubbles is pretty lowtech & not very accurate, the dwyers cost 65 $ makes life MUCH easier, now that I have them, I wonder why I didnt buy them years ago!

I had a knop-c on my first tank, it couldnt keep up with the load, I was running it hard as i could. I added a 2nd chamber, it increased the effluent dkh by 35 % and raised the effluent ph from ~6.5 to 6.8 it was a win/win situation! If I remember, the effluent was running about 2.7 lph and the effluent was ~34 dkh

I ran the co2 so fast into the knop, that it was building up in the 2nd chamber, I ran the 2nd chamber flow from top down, I had a purge valve, so I could bleed off the buildup co2 from the 2nd chamber, I ran that little knop as hard as it could go (still have it on the shelf too)

The knop was on a 55g sps/clam tank, totally full of sps, the calcium/dkh load was pretty high, well extreemly high, I had to supliment with cacl2 and buffer prior to adding the 2nd chamber, the reactor did keep up for a while, but the ca demand increased at an extreem rate when the tank started to really get full..

 

[Osama]

I use my neptune controller to shut of my Nielsen reactor dosing pump IF my main tank pH rises above 8.4 which sometimes happens during the day. I feel this is better than shutting the Nielsen totally during the day. My Nielsen continues to stir the Klalk at a preset duration even when the doser is off. Once the pH drops to 8.2-8.3 then the doser is back on. In effect my Nielsen shuts off about 4-6 hrs from mid day to early evening. My calcium reactor is always on and I am still adjusting as suggested above my CO2 bubble rate & drip rate for optimum output of alk & calcium. I do however have my controller set to shut off CO2 IF for some weird reason I am not home and the pH drops too low like 7.8 from 8.2-8.4. This is only a safety net and not a way to improve alk & calc level or reduce Co2 levels.

 

[clk2609]

thanks everybody.

doing much research on reefs.org and also ran some tests on my effluent.
not good: like i said before, pH of effluent 6.6

here is where problem is: alk only 10dKH, Ca at 375ppm.....

my tank alk is running at 9dKH, Ca 375ppm, so i will start over according to the Knop instructions:

120 drips per minute, says to do 20 bpm CO2, but i am doing 30bpm....reasoning, my SuperCalGold media may not be breaking down enough so i will depress the pH even more to see if there is a difference. i will let this run overnight and check alk and Ca of effluent in morning.

I wonder if i received the wrong media from Marine Depot....i ordered SuperCalcGold but it came in a clear bag....wonder if i just got some bad stuff.....i will call them if my tests are still out of whack....will most likely go to CaribSea ARM.

let me know what anybody thinks about this reasoning.

 

[clk2609]

did some more searches and seems that some people have been having a problem with SuperCalc Gold with it not breaking down enough.

i will post another thread about this opinion, see what everybody that helped me thinks.

Korallath, Geo Marine or CaribSea ARM media

Heard some really good things about ARM but can get hair algae outbreaks, possibly from phosphate

Korallath, bigger grains but more expensive, worth the expense?

Geo Marine, cheaper...have not heard anything about this

pretty much between the Korallath and ARM

let me know your opinions

 

[KenH]

CLK2609, saw your message.

I think you have been given some good info here. I run my reactor (A PM CR622) using ARM media and I adjust my CO2 to get a ph of 6.6 in my effluent. This usually amounts to about 100bbp in my setup. The effluent is rapid drips, but not quite a steady stream. I tend to fine tune the pH when I am close to my target by adjusting the effuent rate rather than the CO2 as my regulator tends to be hard to get fine adjustments out of.

I also do not like the idea of a pH controller other than perhaps as a fail safe to shut down the reactor if the tank pH drops below 7.8 or so. One more thing to go wrong and and having the pH cycling up and down in your reactor is probably just making it harder to figure out what is going on.

If you are running a pH of 6.6 in your effluent and are only getting 12dkH out, I think either your media is at fault (not dissolving worth a darn) or your test kit is bad or you test method somehow has a flaw.

Make sure you're using a good test kit like Salifert and not something like the Red Sea ones. Also, many people dilute the effluent sample with distilled water to get the reading within the test range of the test kit they are using. Make sure you are taking that into proper consideration if you are diluting your sample. Lastly, make sure that your pH probe is calibrated. Only being a couple of points higher than you think you are on pH can seriously decrease the effectiveness of the reactor. I try to keep mine between 6.55 and 6.65 or so. My reactor set up as I noted above goes through about 6lbs of ARM every 3 months or so. I have not tried any other media because I have been happy with the results from the ARM.

--- Ken

 

[clk2609]

thanks KenH, i do use Salifert Alk/dKH with RO water. Calibrated my pH probe a week ago just in case. i honestly think it is my media.

Have you heard any stories about hair algae breakouts in conjunction with ARM? looks like it is working for you.

thanks
chris

 

[Gatortailale1]

I always recommend people people read this article by Sanjay Joshi; especially the bottom section under "reactor operation"

http://www.animalnetwork.com/fish2/aqfm ... efault.asp

Jhood has some good advice in this thread too.

IMO I don't think 30 bubbles per min is enough co2 to dissolve your media. I would try a week or so slowly ramping up your co2. I also think that most people measure their effluent drip in ml. Just use one of your old b-ionic dosing cups and a watch and check the drip rate.

Just remember it will take time to see results of any change you make - only increase bubble rate 10 bpm at a time and wait 24 hours or so b/w changes.

I would ramp up to 50 to 80 bubbles if I were you over a 3 week period and see what that does to effluent ph, alk readings. at that right I would try a 60 - 100 ml / min drip rate. Each tank a little different so hard to just tell you numbers to run it at.

Don't remember reading it above, but remember that reactor really used to "maintain" calcium and alk levels, should NOT be used to raise them in your system. Use other trace element supplements to get alk and cal to desired level and then run reactor at a level that helps maintain the levels.