Long term alkalinity swings

[Naw042]

Hi all,

I was wondering how much alkalinity swing over time is considered "stable". I know Alk may drift with the daily light cycle, but I'm specifically curious about variability over days or weeks.

I started using a dosing pump and 2-part about 4 months ago and have been working on getting my tank stable. It seems that sometimes it'll be perfectly consistent for weeks, but other times it'll swing up and down a bit from day to day and other times it'll start trending until I make an adjustment to the doser.

Basically I'm wondering whether I would be pretty close to what is considered "stable" or do I still have a ways to go if I'm bouncing between 8.5 and 9.5 dKH from month to month.

More info about my setup...

I always test alkalinity around 6 or 7pm.

I was using ESV B-ionic 2 part initially, but switched to Triton 4-part on 12/23. I'm currently dosing 9mL of each component at 30 minute intervals spread evenly throughout the day.

My pH has also always been low with pretty wide daily swings. Lately it's been swinging from ~7.75 at night to 7.9 during the day.

Display is 75gal
Sump is 20gal with skimmer and lots of chaeto growth
Tank is ~7 months old mixed reef. My softies and SPS grow like weeds. Mixed results with LPS (e.g. elegances and acanthos look happy but euphyllia haven't grown much and several favia frags have died).

 

[Randy Holmes-Farley Verified Community Expert]

Any answer I would give us mostly guessing, but the slower the change is the bigger is going to be ok.

 

[King Turkey]

Open windows more ph will swing less. A swing has to do with O2 and CO2. Alk buffers and will help keep it up but equally important is ioe ing windows.

 

[UCF Alum]

Open windows more it will swing less. A swing has to do with O2 and CO2. Alk buffers and will help keep it up but equally important is ioe ing windows.

Im sorry but that’s incorrect. Your alk will not swing if the windows are open or not. pH will. Gassing off the Co2 from the tank with fresh air will raise the pH.
In answer to Naw042 question: I’d say it depends on what type of coral you have. Acros may not like alk over say 9, but can tolerate swings in the 7’s or 8’s within .4 per day. My tank swings .1 per day. The less you can keep the swing the better long term success you will have.

 

[King Turkey]

Im sorry but that’s incorrect. Your alk will not swing if the windows are open or not. pH will. Gassing off the Co2 from the tank with fresh air will raise the pH.
In answer to Naw042 question: I’d say it depends on what type of coral you have. Acros may not like alk over say 9, but can tolerate swings in the 7’s or 8’s within .4 per day. My tank swings .1 per day. The less you can keep the swing the better long term success you will have.

o no I miss read his post I thought this was talking about ph. as I said alk will help keep ph up. I did not once mention opening windows to raise alk. sorry about raising your blood pressure. -cheers.

 

[King Turkey]

Hi all,

I was wondering how much alkalinity swing over time is considered "stable". I know Alk may drift with the daily light cycle, but I'm specifically curious about variability over days or weeks.

I started using a dosing pump and 2-part about 4 months ago and have been working on getting my tank stable. It seems that sometimes it'll be perfectly consistent for weeks, but other times it'll swing up and down a bit from day to day and other times it'll start trending until I make an adjustment to the doser.

Basically I'm wondering whether I would be pretty close to what is considered "stable" or do I still have a ways to go if I'm bouncing between 8.5 and 9.5 dKH from month to month.

More info about my setup...

I always test alkalinity around 6 or 7pm.

I was using ESV B-ionic 2 part initially, but switched to Triton 4-part on 12/23. I'm currently dosing 9mL of each component at 30 minute intervals spread evenly throughout the day.

My pH has also always been low with pretty wide daily swings. Lately it's been swinging from ~7.75 at night to 7.9 during the day.

Display is 75gal
Sump is 20gal with skimmer and lots of chaeto growth
Tank is ~7 months old mixed reef. My softies and SPS grow like weeds. Mixed results with LPS (e.g. elegances and acanthos look happy but euphyllia haven't grown much and several favia frags have died).

I usually have a .5 dkh change. if corals are happy then you are just chasing numbers. 7 moth old tank how big are corals how many? pics? I would suggest just to keep testing and getting the dosing down. but it will change over time as corals grow so testing sorta does not stop.

 

[Randy Holmes-Farley Verified Community Expert]

Open windows more ph will swing less. A swing has to do with O2 and CO2. Alk buffers and will help keep it up but equally important is ioe ing windows.

only CO2 Impacts pH, not O2.

 

[King Turkey]

only CO2 Impacts pH, not O2.

got it

 

[Naw042]

I usually have a .5 dkh change. if corals are happy then you are just chasing numbers. 7 moth old tank how big are corals how many? pics? I would suggest just to keep testing and getting the dosing down. but it will change over time as corals grow so testing sorta does not stop.

Here's my tank. Pretty well stocked for 7 months but still some room for everything to grow out a bit more. You can see that most of them are happy and have grown a lot, but I do have occasional LPS deaths.

I've never heard that acro don't like 9+ dkh. I'll try to gradually get it down closer to 8ish.

I'm going to start a separate post about my low pH once I get the Alk stable and I know that's not a factor. I live in SoCal and have doors and windows open most of the time so I don't think CO2 is the issue.

 

[King Turkey]

Nice looking tank. Haven't heard of em not likeing high alk.

 

[Hemmdog]

Here's my tank. Pretty well stocked for 7 months but still some room for everything to grow out a bit more. You can see that most of them are happy and have grown a lot, but I do have occasional LPS deaths.

I've never heard that acro don't like 9+ dkh. I'll try to gradually get it down closer to 8ish.

I'm going to start a separate post about my low pH once I get the Alk stable and I know that's not a factor. I live in SoCal and have doors and windows open most of the time so I don't think CO2 is the issue.

Beautiful tank. If you want to fix pH, CO2 scrubbers are amazing. I swear by mine, @bubbaque turned me onto them. So much more stability when you don’t have to worry about opening windows and things which will have minimal effect anyways if the skimmer is in a closed cabinet like the majority of reef tanks.

 

[jtone_philthy_aquatics]

Here's my tank. Pretty well stocked for 7 months but still some room for everything to grow out a bit more. You can see that most of them are happy and have grown a lot, but I do have occasional LPS deaths.

I've never heard that acro don't like 9+ dkh. I'll try to gradually get it down closer to 8ish.

I'm going to start a separate post about my low pH once I get the Alk stable and I know that's not a factor. I live in SoCal and have doors and windows open most of the time so I don't think CO2 is the issue.

love the setup dude! Hope everything’s going well with your system if you still have this one up and running