Overnight, I allowed my manually mis-tuned CaRx to raise my tank's Alk over 11dkh - how best to lower back to 9?

[Rst]

Up to yesterday, my tank's alkalinity has been running between a low of 9dkh rising at night to 9.9dkh using a apex controller to control my CaRx. I didn't like my large nightly swings. So now I decided to turn off the automation and try to tune the CaRx completely manually. I woke up this morning and found my tank's alkalinity over 11 and a few corals were suffering.

Yesterday my CaRx was manually started up as follows: Reborn media; 25bpm; Effluent Flow 25ml/min; sump & display tank 150gal heavily stocked with corals & fish; dosing Kalk only during the night;

I still want to run & tune my CaRx manually from now on. But first, what is the best way to lower my tank's alkalinity back down to a my desired 9dkh level? Do I just turn off the CO2 bubble supply for a few days but keep my CaRx's effluent flow running? Or should I turn OFF both CO2 and effluent flow?

Thanks

 

[KrisReef]

Just waiting for my lights to ramp up before I can send a few pictures. As you will see later, I have really clobbered one of my SPS colonies.

2 things
1jda’s method is the best way to focus on your goals. Dripping just enough to keep your alk stable is the goal.
2 find the calcRx drip that keeps alk stable and then stop tinkering to avoid more swings.
My stability is linked to the effluent flow. If the tank starts eating more alk I increase the flow through the calcRx to make up the use, or visa verse. I try to keep it the same level each day at the same time of day but the critters grow and the amount needed can change along the way as things grow.
Hth

 

[Rst]

Could we also get the tank water volume (without sand / rock), the amount of kalk you were dosing at night, and the alkalinity of your reactor's effluent?

Sure. So my combined total net water volume together with the sump water is approx 145 gallons. The overnight kalk (before I turned the kalk dosing OFF yesterday) was 1.66 gallons per night. This pretty much matches my entire current daily evaporation rate. And in terms of my CaRx's effluent, which I completely temporarily shut off both the flow and the CO2 supply (until I will get back to my desired alkalinity level) was set at approx 25 dkh. It was the combination of the overnight kalk dosing and the incorrect Apex programming of the CO2 bpm along with the my set Flow rate that got me into trouble in the first place.

 

[hunterallen40]

Sure. So my combined total net water volume together with the sump water is approx 145 gallons. The overnight kalk (before I turned the kalk dosing OFF yesterday) was 1.66 gallons per night. This pretty much matches my entire current daily evaporation rate. And in terms of my CaRx's effluent, which I completely temporarily shut off both the flow and the CO2 supply (until I will get back to my desired alkalinity level) was set at approx 25 dkh. It was the combination of the overnight kalk dosing and the incorrect Apex programming of the CO2 bpm along with the my set Flow rate that got me into trouble in the first place.

Whoops, sorry, could I also get the flow rate out of the reactor? I'm running some numbers

 

[Doctor Derp]

Wow, this morning my Alkalinity has only dropped from 11.1 to 10.8 in 24 hours. At this rate, it will take a week get back to 9. In the meantime, one of the hard coral tips have turned partially white. I wonder if there is a faster way to bring my alkalinity back down to near the original level? I guess doing a water change replacing 50% of my tank water (75gal) would work faster but that's rather drastic. Maybe adding some acid slowly would be a better solution? Has anybody ever try that?

Nothing good happens fast in a reef aquarium. Let it fall naturally on its own, or you're just going to add more stress on top of what your animals are dealing with. Take this as a warning, please..

 

[Rst]

2 things
1jda’s method is the best way to focus on your goals. Dripping just enough to keep your alk stable is the goal.
2 find the calcRx drip that keeps alk stable and then stop tinkering to avoid more swings.
My stability is linked to the effluent flow. If the tank starts eating more alk I increase the flow through the calcRx to make up the use, or visa verse. I try to keep it the same level each day at the same time of day but the critters grow and the amount needed can change along the way as things grow.
Hth

Hi Kris,
I thought the following advise was correct: To raise the effluent alkalinity making it more potent, you would need to lower the effluent pH by increasing the CO2 bubbles per minute OR decrease the effluent flow rate to increase the dwell time inside the reactor.

Is my statement above still correct? Your advise seems to say when the tank starts eating needing more alk due to coral growth, you INCREASE the flow. But doesn't my statement above conterdict this, meaning you should DECREASE the flow through the reactor in order to make up the use? I guess I am still confused.

 

[KrisReef]

I have a pH controller to keep the reactor steady. I increase flow through as the alk demands increase. Jda’s method tunes the skimmer to work without a pH controller and adjustments still need to be made as consumptions change. So, our methods are not the same but adjustments are. Tune it and adjust it as needed.

 

[Rst]

Whoops, sorry, could I also get the flow rate out of the reactor? I'm running some numbers

Ok, before I turned off the CaRx for a few days, I was trying different combinations of bpm and flow while still keeping the effluent @25dkh. So my last settings were 25bpm and 25ml/min flow. But this is, along with the Kalk dosing, is what got me into trouble when the tank reached over 11 dkh.

 

[Dburr1014]

Hi Kris,
I thought the following advise was correct: To raise the effluent alkalinity making it more potent, you would need to lower the effluent pH by increasing the CO2 bubbles per minute OR decrease the effluent flow rate to increase the dwell time inside the reactor.

Is my statement above still correct? Your advise seems to say when the tank starts eating needing more alk due to coral growth, you INCREASE the flow. But doesn't my statement above conterdict this, meaning you should DECREASE the flow through the reactor in order to make up the use? I guess I am still confused.

Keep your ratio of bpm/mlpm.
Tune up or down but keep that ratio.

 

[Dburr1014]

Ok, before I turned off the CaRx for a few days, I was trying different combinations of bpm and flow while still keeping the effluent @25dkh. So my last settings were 25bpm and 25ml/min flow. But this is, along with the Kalk dosing, is what got me into trouble when the tank reached over 11 dkh.

So you do know your ratio, this is all you need to keep it tuned.
It may change from time to time but for a mild adjustment, just keep the ratio.

 

[Rst]

I have made a .mp4 video of my tank on my iPhone that is 137MB. Sorry but this forum says it's too large to upload. I probably can send it to you if I have an email address.
Ron

 

[Gumbies R Us]

I have made a .mp4 video of my tank on my iPhone that is 137MB. Sorry but this forum says it's too large to upload. I probably can send it to you if I have an email address.
Ron

Try and make it a YouTube link that would work

 

[Rst]

Try and make it a YouTube link that would work

ok I have tried to make a video link (my 1st time creating a video link on utube). Don't know if or when this link will work, anyways here is the link:



Can you and/or others Let me know if this link works?

 

[Rst]

Try and make it a YouTube link that would work

Thanks. I just finished putting my 1st tank video ever up onto utube using a utube link.

 

[Rst]

Nothing good happens fast in a reef aquarium. Let it fall naturally on its own, or you're just going to add more stress on top of what your animals are dealing with. Take this as a warning, please..

I will now try to follow the doctor's orders and make my changes slowly. Thanks for sharing.

 

[Dburr1014]

Link works, nice system.

 

[Rst]

So you do know your ratio, this is all you need to keep it tuned.
It may change from time to time but for a mild adjustment, just keep the ratio.

Once I have found my ratio, and then later on after my corals have grown more, how do you adjust the ratio when the adjustment needed is NOT mild? For example if my current working ratio was 24 ml/min flow & 6bpm CO2 (a magic number of 4), don't I just say increase the flow to 48ml/min and raise the bubbles to 12bpm? Would this same ratio likely cover a more drastic needed adjustment?

 

[Dburr1014]

Once I have found my ratio, and then later on after my corals have grown more, how do you adjust the ratio when the adjustment needed is NOT mild? For example if my current working ratio was 24 ml/min flow & 6bpm CO2 (a magic number of 4), don't I just say increase the flow to 48ml/min and raise the bubbles to 12bpm? Would this same ratio likely cover a more drastic needed adjustment?

Yes, probably not that much, but yes.

 

[Doctor Derp]

I will now try to follow the doctor's orders and make my changes slowly. Thanks for sharing.

I'm not a real doctor, but I did stay in a Holiday Inn Express last night.

 

[Spicy Reef]

ok I have tried to make a video link (my 1st time creating a video link on utube). Don't know if or when this link will work, anyways here is the link:



Can you and/or others Let me know if this link works?

This looks awesome! U R on the right track, everything looks happy
I can't see any obvious burning or receding, are you noticing any changes?

 

[Rst]

This looks awesome! U R on the right track, everything looks happy
I can't see any obvious burning or receding, are you noticing any changes?

Yes. Look at the one large colony I zoomed in on with 1/2 of the branches that turned completely white and the other 1/2 of this same colony where the tips are also white. This is found at the 33 to 49 seconds mark in the video.

But otherwise the other corals seem fine. Thanks for the complement. This tank was a huge time consuming effort, but being addicted was the key

Oh I need to say that I could have never have achieved anywhere near this success without the very generous time taken to answer my many ongoing questions by so many of the selfless reefers right here in this and the other R2R forums.

Thanks to Shirak, Randy Holmes,Reefaholic,Zombieengineer,HuduVudu,bkhunt,jda,dbr_reef,jsker,Dburr1014,krisreef,,hunterallen40,Docter Derp, and many others