alkalinity and pH swings, calc reactor?

[clk2609]

set up KnopC calcium reactor 6 weeks ago and need some help adjusting if anybody out there has experience with KnopC or with reactors in general, i would really appreciate it.

110g reef tank, 20 bubbles/min CO2, effluent rate of 2 drops/second,
pH of effluent is 6.3, hardness of effluent is 20dKH, now comes my tank which i am having an problem with the alkalinity(hardness). the pH swings from 7.85-8.20, hardness is only 6.1dKH, calcium only 350ppm.
of course i would like to bring all these parameters up.

should i increase the CO2? or have more effluent? instructions are rather vague.

tank is doing fine but not thriving, i still add iodine and strontium, was using Calmax part A and B for buffering and calcium requirements and did not see vast improvement. i set up this Knop so i would not have to add Calmax and kalkwasser in the make-up water.

thanks, sorry so long
chris

 

[Jeff Hood]

Chris,

First I will address the setup of your reactor. The output of your reactor should be tuned to maintain your alk and calcium levels not really to raise them. You will do this mostly by trial and error but you will get there.

Now, you mention your rates of Co2 and your dropps and the resultant pH of the output. By those numbers you should increase the drip rate and leave the Co2 rate alone. Check the pH change this causes and adjust until the pH raises to around 6.5 to 6.8 Wait 12 to 24 hours between changes to let things settle out. Once you get things set with a pH of 6.5 to 6.8 then leave it alone for a while.

Next. you need to raise your alk and calcium up to desired levels with some additives and which brand you use is not that important. Do it in a balanced method. In other words, don't just dump a ton of Seachem Reef Builder in all at once. Add the recomended amount every day of both the alk builder like Reef builder and the Calcium supplement such as seachem Reef complete. Alternate your doses of each to raise your totals up all the while your reactor is running.

Once your levels are where you want them then leave the tank alone and see what happens with your levels. Do they fall, stay stable or continue to rise? That is when you decide weather or not to increase the output of your reactor. repeat the process and you will eventually reach a point where your reactor can keep up. This all depends on your calcium usage though and you may in the future reach a point where the reactor can not keep up because of its size and the rate at wich you are pumping tank water through it.

If you need to increase the output then just increase the drip rate and then add Co2 to drop the pH back down into the 6.5 to 6.8 range.

Good luck.

Jeff

 

[clk2609]

thanks jeff, great ideas and i will try them. all sounds good.
chris

 

[fudge1]

Chris,
No offence intended to jeff, but i would have to disagree somewhat with his method.

I would guess you need to raise (BPM&DPM)both somewhat,your bubble count seems way low.
I presently run my reactor at 125 BPM,with an effluent of about 85 mls a minute.
For a loaded 150 sps tank (some lps).

Do not combine additives with it,it defeats the purpose of your reactor,aswell it will not give you a true estimation of what your tank is depleting as far as Ca++ and Alk,nor will it help much with means to correct it with the use of your reactor.......just bump the CO2 up a few notches,and leave your efluent alone.
When your alk reaches required levels(test after 2-3 days per adjustment,say of 5-10 bpm),measure calcium,then bump both up accordingly.

Once your alk sits at a higher level,and has evened out,your ph will not spike/drop much at all.
FWIW,your present spikes are no different than most peoples range from day/night.

Marc.

 

[clk2609]

wow, little dilemna here, what to do. let me do some more research. Fudge, what type of reactor do you have? my 110g is not loaded with SPS yet, but would like to get to that point. mainly soft and some hards, just trying to take my time. i am getting varying advice from other parties also. most say i should try to get my effluent pH up to 6.5-6.8

i will try to figure something out, thanks to both of you for taking time out to help me out

chris

 

[Jeff Hood]

I agree with Fudge that your bubble count is low but that is realy irrilivant right now. The main thing is to get your pH of the output near the 6.5 range. If its too low you could plug your reactor and turn your media to sludge. Your pH seems low and that tells me you either need to decrease the Co2 rate which is already low or increase the outflow to raise the pH a little. As the last statement on my above post, once you find out your demand then you can increase both to meet that demand to get to equalibrium. You don't need to match what others use because everybodys demand is different. You may end up with a bubble rate of only 40 per min or you may need 200 depending on the tank and size. Just understand how the three ( Co2, flow and pH) are related together.

There is no point in maxing out your reactor at first with a small calcium demand until you know what that demand is.

I have to also disagree about the supplements. Most would agree that the reactor is used mostly to keep your levels where you want them and not to raise them up where you want them. I never ment that the supplements were to be continued after you get the levels up only to get them there.
I have never had any problem with using Reef Builder and Reef Complete calcium in conjunction with my Calcium reactor. Once I build up my levels they have remained stable ever since.

It is possible to raise your levels with the reactor don't get me wrong but most don't use it this way.

Jeff

 

[clk2609]

thanks jeff, that does sound logical... i measured my effluent pH yesterday and it was 6.2pH, so i increased the effluent outflow and just turned back CO2 just a little and this morning effluent is 6.6pH which is where i want it, now i think i am going to do the additives to get my pH normalized and calcium up to 400, right now it is just above 350ppm

thanks a bunch, give me other advice if you can.
chris

 

[Gatortailale1]

I found this article by Sanjay Joshi helpful. Especially the last section on reactor operation
http://www.animalnetwork.com/fish2/aqfm ... efault.asp


HTH

Craig

 

[fudge1]

Fudge, what type of reactor do you have?

Hiya chris,
I currently run two reactors,one is based on sanjays design,and ive used it with his original reverse flow design aswell.(didnt work satisfactory at higher co2 rates,due to bubbles eventually lifting media)this one is 4' X 4" diameter.
The one on my display tank is based after Knops design i believe.(its both in and outs for the circulation pump run through the reaction chamber right?)
It stands slighlty bigger though at 38" X 6" diameter.

mainly soft and some hards, just trying to take my time. i am getting varying advice from other parties also. most say i should try to get my effluent pH up to 6.5-6.8

I do agree that your media can turn to sludge,but ph of the reactor may run optimally at a whole range from 6.3 to 6.8.
It really all depends on type of media being used,one reactor i need to keep the ph at about 6.4,due to running just your run of the mill media in it,to keep up with demands.
Its easiest to tune reactor according to your tank alkalinity,usually you can guess if calcium is way high,the alk will be way low,and visa versa.


Sure, you can use your reactor to raise Ca and alk,thats what there made for,if somethings low...you just bump her up a notch.

Either way you use will work,and eventually even out soon.
But i am sure it will be difficult for you to raise tank alkalinity without bumping co2 up eventually,and then both adjustments up incrementaly once stocking really begins.

Good luck,Marc.

 

[Anonymous]

The reactor will add 1.4 dKH alkalinity for every 10 ppm calcium. If you use the reactor only to get to 400ppm calcium, your alk will be a little high--about 13dKH. To avoid doing that, you'll have to add a calcium chloride product for a bit to raise calcium alone.

 

[Chucker]

110g reef tank, 20 bubbles/min CO2, effluent rate of 2 drops/second, pH of effluent is 6.3, hardness of effluent is 20dKH, now comes my tank which i am having an problem with the alkalinity(hardness). the pH swings from 7.85-8.20, hardness is only 6.1dKH, calcium only 350ppm.
of course i would like to bring all these parameters up.

Question pour vous..... as for the pH swings, are those readings taken at the same time of day, or are those the extremes in a cycle?

Keep in mind that in general our tanks are waaaaaay too small to properly buffer the CO2 from respiration during the dark hours, hence depressing pH. CO2 is used up during photosynthesis, which results in higher pH readings during the daylight hours.

 

[plankton123]

Chris,

Recalibrate your pH probe just to make sure you're not making something out of nothing.

Good luck.

SCott

 

[clk2609]

i bumped up the effluent and pH is 6.5 and have been using my CalMax part AandB and will do this for about 10days to see if there is any alkalinity and calcium change. My calcium measured 360ppm today.

I did calibrate the pH probe 2 weeks ago just in case with ph7 and 10.

the pH swings are extremes from night to day, but i have a refugium with opposite light cycle to try and compensate with the swings.
i think if i can get my alkalinity and calcium under control or at a level i want then the tank might equalize.

let me know of any more advice and thanks for the article, i have read it before and it was helpful

chris

 

[Carpentersreef]

...... 8O ....Whew!

Throw an electronic controller on the CO2 tank with a probe in the reactor.

Mitch :wink:

 

[clk2609]

hey mitch, thanks for the reply. i do have a pH controller right how for the CO2 but the probe is in the sump and turns off CO2 at pH of 7.8, do you think i should put probe in effluent?
thanks
chris

 

[plankton123]

OK It wasn't the pH probe.

Here is another dumb suggestion. How big is your skimmer? Skimmers do a great job in making sure your water is well oxygenated AS WELL as getting rid of excess CO2. Assuming you are not dumping CO2 into your tank then you might want to try increasing the aeration of your tank.

Let us know what happens.

Scott

 

[clk2609]

how should i increase airation? i have two genX pumps with 4 outlets into the tank right now for about 18X turnover rate in gallons per hour for a 110g tank. protein skimmer is about 36" tall and 4" diameter, let me know what you think, thanks
chris

 

[Carpentersreef]

hey mitch, thanks for the reply. i do have a pH controller right how for the CO2 but the probe is in the sump and turns off CO2 at pH of 7.8, do you think i should put probe in effluent?
thanks
chris

Hi chris,
It would be best if you had the probe in the reactor and adjusted to turn off the CO2 at about 6.4. and back on at 7.5. (I think that's what I have mine set at...it's been a while since I calibrated it.)

Mitch