Stabilizing Alkalinity & Calcium Levels - Help!

Randy Holmes-Farley · Dec 23, 2015

huskerreefatl said:
I have not since I avoid large ph swings but i have read in the past to avoid them since fish and inverts tend to not like them. My biggest swing may be 0.2 in a 24 hour period. Many dosing discussions talk about dosing alk at night since that is the lowest ph period.

Yes, keeping the low pH from dropping as low as it might otherwise do may be an important reason to dose at night. I sometimes advise that, but not because of the swing, but more because of the low extreme.

IMO, a tank constantly at pH 7.7 is not likely to thrive as well as one that swings from pH 7.8 to 8.3 daily. But there's not really much hard evidence on that issue.

There are also possible reasons to dose more alkalinity during the day to stabilize alkalinity as some folks have found that most of the alk usage occurs during the daylight hours, so they dose more during the day to stabilize it.

Whether limiting the pH drop or minimizing the fluctuations in alkalinity are more important, I do not know, and it may vary based on which creatures are in the aquarium.

FWIW, if you really want to minimize the pH fluctuations, more aeration will do it. Complete aeration will eliminate any pH swings, unless the CO2 in your air fluctuates, or the alk level in the tank changes significantly.

huskerreefatl · Dec 23, 2015

That makes sense on daytime usage. I do know that i am always careful about dosing in the day time, at least in the afternoon, or else my ph will really jump

Cyberdude · Dec 23, 2015

Stop your water changes for a while and see what happens. Was in the same boat months ago for a very long time. New frags had only a 30-40% chance of surviving despite stable water. Significantly reduced water changes and am now happy to report zero losses of frags for the last 8-9 months. I only do a 10% wc every 6 weeks. And only because I want to clean out the bare bottom.

samba_dad · Dec 23, 2015

What are the desired levels of NO3, PO4? At what levels is the system considered ULNS? I am thinking I should lower my Alk to 8 until I get my PO4 and NO3 higher? I am 0.02ppn PO4 and 3 ppm NO3 currently.

twilliard · Dec 23, 2015

Drop po4 down a little and your no3 would be good at that alkalinity level.

Randy Holmes-Farley · Dec 24, 2015

samba_dad said:
What are the desired levels of NO3, PO4? At what levels is the system considered ULNS? I am thinking I should lower my Alk to 8 until I get my PO4 and NO3 higher? I am 0.02ppn PO4 and 3 ppm NO3 currently.

That is not ULNS. ULNS is low enough to begin to starve corals and reduce levels of zooxanthellae in them. There is no special combination of numbers, but at least one needs to be low enough to limit zoox, and I don't think either of those will.

samba_dad · Dec 24, 2015

I have implemented the recommendations I have received so far. Thanks everyone! I am committed to get these levels corrected and consistent/stable. Here is what I have done so far.

1) Set Alk & Ca dosing levels/amounts to be identical.
2) Reversed timing of Alk (during day) & Ca dosing (during night)
3) Stopped GFO
4) Protein skimmer on a timer

I am trying to stabilize Alk at 9dKH, Cal at 450 ppm, NO3 at 3ppm, PO4 at 0.04ppm. The reason the PO4 is higher is because the Red Sea Pro test kit accuracy is 0.02ppm and the color between 0 and 0.02 ppm is so close that I can't really tell the difference. I am concerned my 0.02ppm measurement may actually be 0ppm because I have a tendency to overdose Phosban - which I have corrected.

Here are my measurements thus far as part of this journey =).

12/21/15 (Mon) - Alk: 9.2, Cal: 500 (used all titrant), NO3: 3, PO4:0.02 (could be 0)

Adjusting dosing to 48ml of 2-part (Ca & Alk) per day.

12/24/15 (Thu) - Alk: 9, Cal: 500 (used all titrant), NO3: 3, PO4:0.02 (could be 0)

What should I do about the Ca? This is where I think I have made mistakes in the past - so I need some good advice. In the past, I would shut off my Ca dosing until the level reduced to 450ppm. In the process, the Alk would start to go unstable. Is this what I should do now?

As always, thanks so much for the help! I certainly need it.

Randy Holmes-Farley · Dec 24, 2015

If you want the calcium lower, I'd just turn off the calcium doser for a while.
That should not have much impact on the alkalinity. Keep dosing it as you are.

samba_dad · Dec 26, 2015

Here is another update on my journey to stabilize my critical 4 parameters: Alk, Ca, NO3 and PO4 with targets of 9dKH, 450ppm, 3ppm, and 0.04ppm respectively. It looks like I am close on my alkalinity dosing levels. My NO3 & PO4 are continuing to rise. My Ca is apparently off the charts because I have not dosed it in 2 days and I am still reading the upper limit of the Red Sea pro test kit. I have increased my protein skimmer timer a bit to try to make sure my NO3 does not get too high. No signs of increased microalgae growth. However, I have noticed my chaeto has started to grow more in the refugium - usually it just stays the same size almost always. I am still hopeful I can finally solve this water chemistry challenge.

In addition, I have ordered and mailed off a Triton sample to ensure I don't have anything else out of alignment. Finally, I ordered a Seneye reef monitor to check my PAR levels to ensure I have the correct lighting spectrum. I am confident I have sufficient flow with the recent addition of a pair of Jebao RW4 (850 GPH each) and a Sicce Voyager 3 (1200GPH) on wave makers. I am definitely ready for some SPS growth! Thanks again for all the help everyone! I hope everyone had a great Christmas.

Randy Holmes-Farley · Dec 26, 2015

You can get an actual calcium reading by adding a second syringe of fluid as needed to get to the color end point, and just add the values together.

samba_dad · Dec 27, 2015

I'm posting a few pictures of the SPS that I have that have appeared to either start or finish RTN. In the same tank I have some SPS that have done well. Hopefully, some of these corals might recover/thrive once I get this chemistry issue resolved.

Here are some SPS that have done well in the same tank.

samba_dad · Dec 28, 2015

Another update on my measurements. I seem to have locked in on my alkalinity - yay! I used @Randy Holmes-Farley recommendation and used a 2nd titrant for my Ca test and I am measuring 645ppm in my DT. It has probably been that high since I started this process 1 week ago. Also, I am growing concerned about my NO3 getting too high. I have my protein skimmer running for 12 hrs/day currently. I may go back to 24hrs/day operation.

Questions
1) Should I do anything about my excessive Ca level or just let it drop to normal levels in about 10 days?
2) If protein skimmer does not stabilize nitrate to 4ppm, should I start dosing NoPox? I had dosed vinegar in the past but stopped because my nitrate was a zero.

As always, thanks for the advice!

samba_dad · Dec 28, 2015

Also I forgot to report on my update with switching the Alk to dosing during the day and Ca dosing at night. I previously had this backward and it was causing bigger swings in pH than desired. Under the old/wrong approach, I was measuring 7.91 avg, 7.86 min, 8 max for pH. With the newer approach (Alk during day/Ca during night), I have 8.18 avg, 8.12 min and 8.22 max. So, my pH was swinging almost a full point per day and now it only swings 0.04 per day. Furthermore, the pH remains around 8.2 much more consistently. I was excited about this improvement!

Anxious to get this water chemistry turned around and getting some more success with SPS. Many thanks to everyone for the help!

samba_dad · Dec 28, 2015

I meant to say the swings are about the same for both cases, but the new way is in the pH range it needs to be.

Randy Holmes-Farley · Dec 29, 2015

So I'd just stick to the alk dosing you have and simply monitor calcium as it should slowly drift down.

samba_dad · Dec 29, 2015

Randy Holmes-Farley said:
So I'd just stick to the alk dosing you have and simply monitor calcium as it should slowly drift down.

Thanks Randy. Should I be concerned with NO3 moving to 5+ ppm?

Randy Holmes-Farley · Dec 29, 2015

I'd just keep watching the nitrate to make sure it is a real trend and not just a random variation.

samba_dad · Dec 29, 2015

Oh no! Just noticed I am getting some cyano in my DT and loads of it in my refugium. It is growing over my acans. I have increased flow and will slow down my feeding of corals to once every two days. Any other ideas?