PH, Alkalinity and dosing

[Art2249]

Just like to pass along something I learned over the past 2 days. I'm sure many people have already discovered this. I've been dosing ALK at night to help with PH swings. I always tested ALK at the same time of day and assumed it was stable. I decided to test in right after the doser shut down and again right before it started back. Alk had dropped from 8.4 to 8.0 during the day. I assume that's when it gets used up. So I have reset my doser to spread throughout the day better. Today the alk remained steady testing 3 times.
morning 8.5
midday 8.4
evening 8.4
It hasn't really effected the PH that much so far. In fact the PH swing has been smaller. I still haven't tested in the middle of the night but plan to. Just to see.

 

[JimWelsh]

You might find this interesting: Alk Swing @ Night

EDIT: There is more interesting stuff in this same thread, starting on page 1: Alk Swing @ Night

 

[Art2249]

You might find this interesting: Alk Swing @ Night

EDIT: There is more interesting stuff in this same thread, starting on page 1: Alk Swing @ Night

Thanks for the link. I just took a screenshot of ph and I think the swing has actually been reduced along with the alk swing

Needa few more days of data though.

 

[Randy Holmes-Farley Verified Community Expert]

Adding high pH alk additives at night only will reduce the daily pH swing, but may increase the alk swing relative to 24/7 dosing.

Dosing alk only during the day may make alk most stable, while allowing for more pH swing and what type of alk additive (very high, high, or no pH boost) to use may depend on the peak pH attained during the day.

I'd use the pH bottom to decide which is more important, alk or pH stability. If the pH bottom is below pH 7.7, I'd focus on bringing up the pH bottom.

 

[Art2249]

Adding high pH alk additives at night only will reduce the daily pH swing, but may increase the alk swing relative to 24/7 dosing.

Dosing alk only during the day may make alk most stable, while allowing for more pH swing and what type of alk additive (very high, high, or no pH boost) to use may depend on the peak pH attained during the day.

I'd use the pH bottom to decide which is more important, alk or pH stability. If the pH bottom is below pH 7.7, I'd focus on bringing up the pH bottom.

Thx for the reply. I use soda ash and have changed the dosing schedue from night only to 4 hours after lights com on off for four hours and then resume . here is the lighting schedule.

here is the new dosing schedule,

Calcium doses on a 30 minute offset 24 hrs a day. I do have a question about alk levels and nutrients. My phosphate is around 10 ppb. Whenever I try to raise it I get an algae burst and it drops right back down. Nitrates are around 4 ppm. On a side note my chalurpa in the fuge died back significantly when I stopped adding phosphate. The phosphate was exasburbating a hair algae issue in the display. I have a gold spotted rabbitfish almost through QT and hope he will help me. He eats sheet algae like a herd of pigs. So we'll see on that. Still haven't added a tang. tank is 8 months old.
What would be a recommended alk level for nutrients at phoshpate 10 ppb and nitrate 4 ppm?