pH Spike while Raising Alkalinity

[joro]

Now that I finally have gotten past the cycle and have a good amount of fish/coral in the tank, I want to start raising my Calcium, Alkalinity, and Magnesium levels to the desired amounts so that I can begin automatic dosing through my two Neptune DOS units. I ran tests today on these three parameters (plus others) and came back with the following results:

• Calcium: 526 ppm (via Hanna Checker)
• Alkalinity: 6.3 dKH (via Hanna Checker)
• Magnesium:1420 (via Red Sea)

So Calcium and Magnesium seem to be inline - if not a bit elevated - so it appeared that Alk was the main parameter I needed to address with the correction before normal dosing. Using BRS's calculator, it said to I needed to dose about 1057ml of 2-Part (Soda Ash) so make this change which I am splitting up over the next 3 days as to not create too much of a swing.



So today, I dosed 350ml directly in front of the powerheads. The tank was cloudy for a minute or so but cleared up pretty quickly and no ill effects noticeable on either the fish or corals. Once I did this though, I noticed a pretty large spike in pH - rising from around 7.8 to 8.3 directly after the dose. It's been coming down steadily since then but I'm concerned a bit with the remaining two doses and if the "spike" is going to be stressful to either the fish or corals and whether I should be worried about this putting me above 8.3 (even temporarily) now that the pH is elevated?

 

[Eric Tang]

if you have a doser, you should add the buffer slowly over a long period of time so there is no large swings.
you should also keep the same recipe for your buffer. (a common recipe is 164 gram baking soda for 2 liter of RO water). You should split the required dose into a few days and check the alkalinity each day to keep a record of the changes. You may need to adjust the dosing after it has reach your desired level so you can maintain the daily dose of the correct amount without increasing/decreasing the alkalinity.

hope this helps

 

[roberthu526]

350ml at a time seems a lot. How big is your tank?

 

[Randy Holmes-Farley]

pH is fine up to at least 8.55, and there's no reason to worry about it at any level up to that. If you spread out the doses it won't get very high. I do not believe organisms have any problems with pH changes within the normal range. Many may grow faster at 8.3 than at 7.8.

That said, any time you want to boost alkalinity without a pH rise at all (in fact, a small drop) use baking soda instead of washing soda.

 

[Scott.h]

Keep us posted on how the corals react going from 6.3 to 10.0 in three days. I'm curious as to what corals you have, what they look like, and how they react 1-3 weeks from now.

 

[LobsterOfJustice]

Keep us posted on how the corals react going from 6.3 to 10.0 in three days. I'm curious as to what corals you have, what they look like, and how they react 1-3 weeks from now.

Agreed - depending on what corals you have, spreading this dose over 3 days may not even be enough. I would target a change of 0.5 dkh per day.

 

[joro]

Appreciate everyone's quick and thoughtful responses, one of the reasons I love R2R! The pH did come back down slowly overnight and is now hovering back at it's "normal" level - around 7.9. The plan is to re-test the dKH this evening and then make adjustments accordingly with the goal of getting to 10 before I start the normal daily dosing. I'll respond to individual questions below!

350ml at a time seems a lot. How big is your tank?

~400 gallons total water volume

pH is fine up to at least 8.55, and there's no reason to worry about it at any level up to that. If you spread out the doses it won't get very high. I do not believe organisms have any problems with pH changes within the normal range. Many may grow faster at 8.3 than at 7.8. That said, any time you want to boost alkalinity without a pH rise at all (in fact, a small drop) use baking soda instead of washing soda.

Thanks for the tip on the baking soda and it seems there were no ill effects as the levels re-stablized less than 24 hours after the first dose.

Keep us posted on how the corals react going from 6.3 to 10.0 in three days. I'm curious as to what corals you have, what they look like, and how they react 1-3 weeks from now.

This is a newer tank - as in we've had it up/running for about a month now - and we have maybe 15 corals in it currently. Most our LPS but we do have a few smaller SPS frags. All of them were wide open today and haven't lost any color in the past 24 hours since the first dose. I'm curious though on what the downside would be to raising it quicker? I understand that if I overdose that's bad, but staying within normal ranges I would think I'd be safe. Have you had a different experience?

Agreed - depending on what corals you have, spreading this dose over 3 days may not even be enough. I would target a change of 0.5 dkh per day.

BRS suggests no more than 1.4 dKH a day which is why I broke into 3 doses so much higher than that 0.5 dKH you suggested. I'm not opposed to breaking it down into smaller doses, just trying to get a feeling for why I would do it one way or another. Seems to me that as long as I'm not spiking outside of normal ranges, it should be fine over 3 days but this is my first time with two-part so maybe I'm missing something. ;Bookworm

 

[chipmunkofdoom2]

BRS suggests no more than 1.4 dKH a day which is why I broke into 3 doses so much higher than that 0.5 dKH you suggested. I'm not opposed to breaking it down into smaller doses, just trying to get a feeling for why I would do it one way or another. Seems to me that as long as I'm not spiking outside of normal ranges, it should be fine over 3 days but this is my first time with two-part so maybe I'm missing something. ;Bookworm

If there's anything we've learned as hobbyists over all these years, it's that generally speaking, stability is key. More specifically, stability of carbonate alkalinity is critical to more sensitive corals. Reef keepers with SPS-dominated tanks strive for as little change in alkalinity as possible. It's uncommon to see a successful SPS tank where alkalinity wasn't very carefully maintained. If it were my tank and it had any corals in it, I would not aim to increase carbonate alkalinity by more than 0.5 dKh per day either.

While it might not hurt anything to increase the alkalinity from 6.3 dKh to 10 dKh in 3 days, what is the practical purpose for increasing it that quickly? What would the harm be in making the increase over a week or two?

 

[Scott.h]

In my experience had I decided to jump that fast in alk, my sps would be smoked, no doubt. Secondly I disagree with brs on being able to raise alk that fast, maybe more importantly, not that high either. Add the fact that its a new tank doesn't help. There are other variables involved to this conversation, and should not be generalized to someone starting out referring to brs. Thirdly I wouldn't keep my alk at 10. Not saying it can't be done, obviously some are, and there are reasons behind it.

I'm not sure how much you've added at this point but I wouldn't add more then you have, assuming now its above the 7 or 8 range. The effects may not show for a few weeks. Now that its done, might as well try to learn and take something away from this.

 

[LobsterOfJustice]

This is a newer tank - as in we've had it up/running for about a month now - and we have maybe 15 corals in it currently. Most our LPS but we do have a few smaller SPS frags. All of them were wide open today and haven't lost any color in the past 24 hours since the first dose. I'm curious though on what the downside would be to raising it quicker? I understand that if I overdose that's bad, but staying within normal ranges I would think I'd be safe. Have you had a different experience?



BRS suggests no more than 1.4 dKH a day which is why I broke into 3 doses so much higher than that 0.5 dKH you suggested. I'm not opposed to breaking it down into smaller doses, just trying to get a feeling for why I would do it one way or another. Seems to me that as long as I'm not spiking outside of normal ranges, it should be fine over 3 days but this is my first time with two-part so maybe I'm missing something. ;Bookworm

Alkalinity stability is literally the most important thing for SPS. I would absolutely expect to lose some SPS going from less than 7 to 10 dkh in 3 days. Honestly I think if you made that jump in a week they'd still be stressed.

 

[joro]

While it might not hurt anything to increase the alkalinity from 6.3 dKh to 10 dKh in 3 days, what is the practical purpose for increasing it that quickly? What would the harm be in making the increase over a week or two?

No specific reason other than I was going on BRS's recommendation which obviously many you all disagree with. I'll re-test today to see where I'm at but is the better rule of thumb not to increase 0.5 dKH/day or would you all recommend even lower than that?

I'm not sure how much you've added at this point but I wouldn't add more then you have, assuming now its above the 7 or 8 range. The effects may not show for a few weeks. Now that its done, might as well try to learn and take something away from this.

Thanks and my understanding was that at the higher dKH levels, the corals tend to grow faster. The range that's touted as "ideal" is between 8 - 12 dKH, so I figured at 10 I would have a little wiggle room in either direction should something go wrong.

 

[Scott.h]

It is possible but here's the issue. Aside from the fact that some sps flat out don't like alk that high, with the system being new its not yet stable. Stability is key. Also there probably isn't a lot of excess nutrients for the corals. When you crank alk or light to a coral asking it to grow without the nutrients, it can't. That's the quickest easiest way to explain.

FWIW when had had undetectable nitrate and phosphate, even adding coral food I couldn't go much above 7.0, no matter how slow I added. Even now with .02 and 2 its at 7.0

 

[joro]

It is possible but here's the issue. Aside from the fact that some sps flat out don't like alk that high, with the system being new its not yet stable. Stability is key. Also there probably isn't a lot of excess nutrients for the corals. When you crank alk or light to a coral asking it to grow without the nutrients, it can't. That's the quickest easiest way to explain.

FWIW when had had undetectable nitrate and phosphate, even adding coral food I couldn't go much above 7.0, no matter how slow I added. Even now with .02 and 2 its at 7.0

Makes sense and FWIW, we are running the ZEOvit system and dosing AcroPower to aid in the nutrients, so we'll see I guess long term how it all works out. Appreciate the feedback!

 

[joro]

Just measured Alkalinity and it's showing at 7.7 dKH which is what I would have expected (a 1.4 dKH increase from yesterday). I'm going to level it out at 8 dKH for now - instead of 10 - which now shows I should dose another ~86ml of Soda Ash. As mentioned prior, no corals and/or fish seem to have any ill effects, in fact I noticed today that my hammer has 3-4 new heads sprouting!

 

[Scott.h]

If I remember correctly doesn't the zeovit system call for 7.0?

 

[Scott.h]

Yes, there is a reason they want you to run near natural sea level conditions. Especially with a product like the zeo system where it's an ulns. You'll see the results of running higher alk in the near future. It doesn't always appear right away.

 

[joro]

So, as with everything in this hobby, if you check the ZEOVit forums there is a lot of debate as to whether this parameter or that parameter needs to be close to NSW to be effective and Alk is probably the most commonly discussed. I've seen the acceptable range anywhere from 7 - 9 dKH and have also seen others running closer to the 11/12 range with success in ZEO, it's all about stability of course. In any case, I do think I'll stick it around 8 for now and measure the results over the next few weeks!