Improving the Dkh swings.

ReefHunter006 · Dec 25, 2020

Hi All, I am looking to improve the stability of my alkalinity and was hoping that I might be able to get some help.

As PH fluctuates I need varying amounts of 2 part to keep up with Alk demands. Intraday swings are in the range of .3-.5 hour to hour in some cases. Alk typically moves up to 8.4 and down to 8.1 averages throughout the week, but the highs or lows for larger fluctuations can exceed those. An example is around the 23rd/24th below where it jumps from 8.07 to 8.5 dkh over the hour.

Last few days of Alkalinity.

Additional Hanna Alk points are in blue. Values typically fluctuate between 8.0 and 8.5 through the week.

12/25/2020 Alk Chart

Other Factors

PH is controlled with a CO2 scrubber and refugium. Nighttime low PH is roughly 7.95-8.1 depending on the age of the media. Daytime high is usually around 8.25-8.36. The PH above 8.4 was an outlier and still uncertain what caused it.

Tank

Specs

Mixed reef
65 Gallons, 60ish gallons net

Dosing

ESV B ionic 2 part, 35-40mls a day VIA Apex DOS
Red Sea Coral Nutrition AB+ 6ml each
Phytopheast alive 2ml
Algaebarn Phyto 30ml
Microbactor 7 2ml
Cheatogro .7-1ml

I would like to narrow my Alk swings as much as I can to promote better sps health. I feel like the bulk of my issue is that the dosing amount changes frequently during the day due to PH changes.

Any suggestions on what I can do to improve these swings? I haven't seen any negative effects on the sps frags yet and they are all over a month old. Most are 2-4 months old. Please let me know if I can provide anything else.

Happy Holidays!

DaneGer21 · Dec 25, 2020

How are you dosing your two part? Apex? Manually?
I use a BRS doser via Apex, after I found out how much my tank uses I broke down the dosing so it would be every 15mins throughout the day instead of large amounts at once or twice, etc.

ReefHunter006 · Dec 25, 2020

DaneGer21 said:
How are you dosing your two part? Apex? Manually?
I use a BRS doser via Apex, after I found out how much my tank uses I broke down the dosing so it would be every 15mins throughout the day instead of large amounts at once or twice, etc.

I'll update the OP. I am using APEX DOS. It usually runs about .3-.5mls every 10-15 mins depending on how I change the dos amount. As PH approaches 8.3 I typically have to increase the dose to 37-39mls. As PH falls to 8 then I need to lower it to 32-35mls to manually combat the swing. Those numbers change more as well as the CO2 media becomes exhausted and the highs/lows for PH change.

EDIT: I wanted to add that I know estimated amount that my tank uses. The problem is that it is a moving target day to day and hour to hour. Keeping the dose at 36mls would get to 8.1-8.4 at 9am throughout the week. I run into an issue that if I don't play with those numbers throughout the day then they swing by .3-.6 dkh within the day due to the increased demand as PH rises from 8 to 8.3.