How stable is stable?

[iemsparticus]

Hey y’all! I’m curious as to how stable everyone is able to keep their tank’s alkalinity, and what variation people would consider stable, and and what point it becomes unstable.

I ask because the Alk in my tank varies between 7.8 and 8.2. This is a fine range for me... I use ZEOvit so I can’t have elevated Alk levels... but I’m wondering about the stability factor.

Thoughts?

 

[krausean]

I aim to keep my alk as stable as I possibly can with my calcium reactor. I only run my reactor during the day, which actually helps keep my pH more stable at night too. My alk varies by less than 0.1dkh throughout the day and night. I doubt this is necessary, but I like it this way. I run my alk at around 10.5

 

[Denisk]

My alk with two part is very stable but as long as it’s in range of .4 dkh range throughout the day. I usually see no problems at least not for me.

 

[madweazl]

I had some ups and downs but have been more diligent lately.

 

[Randy Holmes-Farley]

Hey y’all! I’m curious as to how stable everyone is able to keep their tank’s alkalinity, and what variation people would consider stable, and and what point it becomes unstable.

I ask because the Alk in my tank varies between 7.8 and 8.2. This is a fine range for me... I use ZEOvit so I can’t have elevated Alk levels... but I’m wondering about the stability factor.

Thoughts?

I think it depends greatly on what organisms you keep, but that seems pretty tight to me.

Some folks with auto titrators and auto dosing think they see a bit more growth of some SPS corals when keeping alk even tighter than you are.

 

[iemsparticus]

I think it depends greatly on what organisms you keep, but that seems pretty tight to me.

Some folks with auto titrators and auto dosing think they see a bit more growth of some SPS corals when keeping alk even tighter than you are.

Thanks for the input.

My tank certainly seems happy... it’s been going for a little over 8 months now, and coral growth seems to be hitting it’s stride... just wondered if I should be trying to get the Alk swings tighter than they are or not.

Eventually I may go the auto titrater/doser route... but for now, I use the Hanna checker to tests Alk every day, and dose 2 part.

 

[Myka]

One thing I've found over the years is the tighter you keep the daily swing, the more sensitive the corals become to a swing outside their usual boundaries. In other words, if something screws up (including you), the consequences are usually more extreme. So it's a double edged sword imo.

 

[iemsparticus]

One thing I've found over the years is the tighter you keep the daily swing, the more sensitive the corals become to a swing outside their usual boundaries. In other words, if something screws up (including you), the consequences are usually more extreme. So it's a double edged sword imo.

Ah, now that is an interesting observation. Hmmmm...

 

[kecked]

I can tell you my tank went from 8.4 to 11 and back to 7.6. Cuz I just pump my alk in the overflow once a day. Did this for years with no problem. Run calcium around 400. I grew a monti from quarter size to plate size grew a Dereasa clam to 12”. Until this latest Dino outbreak which started when I went uln, I was great for over ten years. I however only grow candy canes, Fabian, singulara, Zoa, monti, assorted star polyps. So nothing exotic.

I’m setting up dosing and doing it right next. Point is my tanks all over the board and did just fine. Do have auto top off and skimmer. Just hand dosing alk and calcium. I let m6 nitrate hit 10 then dumped cap of ethanol. Dropped down to zero over night. Raised back up over a week or so and repeated.

Lazy I guess.

 

[ZaneTer]

@iemsparticus
I recently moved to automatic testing and dosing. People most often believe that there tank is very stable in terms of Alk but they are only testing once a day, if someone is dosing and testing at the same time every day you will probably find very little variance in each test which makes people think the dkh is solid as a rock. Its not.
I dose 8 times per day and get quite a large daily swing of about 0.8dkh but as i said if i were to take my test results for 3pm every day and just chart them it would look like my dkh is very stable. My KH director is smoothing out the swing quite nicely but its taking some time to fine tune it. ( I dont like the calculations they used and would have preferred a true PID loop)
In my opinion stable is a swing of less than 0.2dkh measured between any two times of day and any days of the week.

 

[iemsparticus]

@iemsparticus
I recently moved to automatic testing and dosing. People most often believe that there tank is very stable in terms of Alk but they are only testing once a day, if someone is dosing and testing at the same time every day you will probably find very little variance in each test which makes people think the dkh is solid as a rock. Its not.
I dose 8 times per day and get quite a large daily swing of about 0.8dkh but as i said if i were to take my test results for 3pm every day and just chart them it would look like my dkh is very stable. My KH director is smoothing out the swing quite nicely but its taking some time to fine tune it. ( I dont like the calculations they used and would have preferred a true PID loop)
In my opinion stable is a swing of less than 0.2dkh measured between any two times of day and any days of the week.

I’m contemplating getting Neptune’s auto titrater when it is released... we’ll see.

 

[ZaneTer]

I am very interested to see how it performs. I wasn’t prepared to wait however long it may be to arrive in Europe. Mind you I am very happy with my GHL.

 

[Randy Holmes-Farley]

I still think it is one of the unknowns of reef chemistry how important alk "stability" is and what exactly that means.

There are different kinds of instability.

Is an alk shift of 7 to 9 dKH at 7 AM every day, followed by a 24 h slow decline back to 7 dKH a problem?

That's a different sort of instability than a tank that varies randomly though the month.

The former may not be much of a problem for a coral to adapt to, while the latter may be more problematic.

 

[krausean]

I still think it is one of the unknowns of reef chemistry how important alk "stability" is and what exactly that means.

There are different kinds of instability.

Is an alk shift of 7 to 9 dKH at 7 AM every day, followed by a 24 h slow decline back to 7 dKH a problem?

That's a different sort of instability than a tank that varies randomly though the month.

The former may not be much of a problem for a coral to adapt to, while the latter may be more problematic.

Any Idea how stable alk is in the ocean, Randy? I tried doing a google search a while ago but couldn't really come up with an answer. I know pH varies somewhat from day to night but couldn't find anything on alk. Too much auto titration advertising lol

 

[Randy Holmes-Farley]

Any Idea how stable alk is in the ocean, Randy? I tried doing a google search a while ago but couldn't really come up with an answer. I know pH varies somewhat from day to night but couldn't find anything on alk. Too much auto titration advertising lol

Alkalinity is almost totally stable, unless you are talking about a closed tide pool or very small lagoon.