Auto Water Changes and dosing schedule/pH?

[aaron186]

I’m running a 100 gal SPS dominated system with auto water changes via Dos and brute cans in garage with water level sensors in the bins. I’m running it from 5pm to 11pm each day because that is when I am home/awake typically and I want to be able to catch it if there’s an issue with tanks running dry or some other alarm.

Im also dosing Alk (Triton which I believe is soda ash) at 10a-3p and calcium at 4a-9a. I run a refugium at night on a reverse schedule and a CO2 scrubber as well.

I’m noticing that l’m getting pH swings where my pH will spike around 8.15 in afternoon during alk dosing and then slowly decline to 7.9 at night and not rise again until alk is dosed at 10a.

I’d like to combat these swings and I assume spreading out my Alk dosing will help but I’m not sure how to do it. I assume dosing during the AWC would be stupid so that removes 6 hours that I can dose from 5-11. Should I change the water faster over a smaller time window? I assume dosing alk during the night would help my nocturnal pH swings, but I was under impression that alk is used more during the day so I’m worried this will upset the SPS frags.

How do you recommend I space out my AWC, and 2 part dosing?

 

[tzabor10]

Are your corals unhappy? Those PH swings seem normal. Alkalinity should be dosed at night and calcium during the day.

 

[Dburr1014]

How much daily water changing are you doing? 6 hours seems like a really long time. I'm doing 1% in my 100 gallon system and it does it between 2:30 and 4:00 in the afternoon.

 

[aaron186]

How much daily water changing are you doing? 6 hours seems like a really long time. I'm doing 1% in my 100 gallon system and it does it between 2:30 and 4:00 in the afternoon.

1 gal per day currently. I’ve been trying to find a sweet spot to keep my phos detectable but under .1

 

[doubleshot00]

Your AWC is not effecting your PH imo. I do a AWC from 3:00 to 4:30 everyday (1.5 gal) and dont notice a thing with my PH. The swing is a combination of you dosing, co2 scrubber and the lights.

 

[aaron186]

Your AWC is not effecting your PH imo. I do a AWC from 3:00 to 4:30 everyday (1.5 gal) and dont notice a thing with my PH. The swing is a combination of you dosing, co2 scrubber and the lights.

Yes I’m not saying the AWC is effecting it but it is altering when I can dose alk since it seems foolish to dose it while the water is being changed

 

[Randy Holmes-Farley Verified Community Expert]

Im also dosing Alk (Triton which I believe is soda ash) at 10a-3p and calcium at 4a-9a. I run a refugium at night on a reverse schedule and a CO2 scrubber as well.

Which exact triton supplement, and why do you think it is carbonate based?

 

[doubleshot00]

Yes I’m not saying the AWC is effecting it but it is altering when I can dose alk since it seems foolish to dose it while the water is being changed

Oh. I dont adjust anything when i do a AWC. Set the doser to start dosing all throughout the day when the lights are on. My alk, cal and mag stay pretty consistent throughout the day. Now if your using something like red sea salt that has high alk i can see you may need to make some adjustments but im an IO guy.

 

[aaron186]

Oh. I dont adjust anything when i do a AWC. Set the doser to start dosing all throughout the day when the lights are on. My alk, cal and mag stay pretty consistent throughout the day. Now if your using something like red sea salt that has high alk i can see you may need to make some adjustments but im an IO guy.

So you just do the water change over the entire day?

 

[aaron186]

Which exact triton supplement, and why do you think it is carbonate based?

Triton Core 7 Flex. I saw a BRS video where they compared the pH change of various 2 parts and triton and soda ash were the same pH change and I believe they hypothesized that it had soda ash in it. Or hinted at it. I think they keep it propriety info on what’s in it.

 

[esquare]

I dose 1/2 gallon of saturated kalk at night and make up the difference in my alk/cal consumption by dosing 2 part (soda ash alk) during the day. I have found this minimizes my pH swings. It probably isn't necessary to worry about the pH swings but I feel anything I can do to stabilize the system will help offset other errors I make

 

[aaron186]

I dose 1/2 gallon of saturated kalk at night and make up the difference in my alk/cal consumption by dosing 2 part (soda ash alk) during the day. I have found this minimizes my pH swings. It probably isn't necessary to worry about the pH swings but I feel anything I can do to stabilize the system will help offset other errors I make

Out of curiosity what do you keep your Alk at? I tried 2 part and kalk but was having issues with my Alk creeping up/stabilizing it

 

[esquare]

Out of curiosity what do you keep your Alk at? I tried 2 part and kalk but was having issues with my Alk creeping up/stabilizing it

I keep it about 9 dkh.

 

[esquare]

I forgot to mention that I am doing AWC with the DOS as well, 1.5% daily on 130 gallon total system volume. I have mine setup to run 24/7

 

[esquare]

Out of curiosity what do you keep your Alk at? I tried 2 part and kalk but was having issues with my Alk creeping up/stabilizing it

I leave the nightly kalk dose at 1/2 gallon and adjust the daily 2 part dose to maintain alk level

 

[Randy Holmes-Farley Verified Community Expert]

Triton Core 7 Flex. I saw a BRS video where they compared the pH change of various 2 parts and triton and soda ash were the same pH change and I believe they hypothesized that it had soda ash in it. Or hinted at it. I think they keep it propriety info on what’s in it.

OK, same pH rise means it is carbonate.

I don't think it matters when you dose alk relative to AWC times. I personally did not try to control that relationship.

Dosing high pH alk additives at night stabilizes pH the most and brings up the low pH end.

Dosing alk additives of any kind during the day stabilize alk the most.

What to do depends on your goals and what you think is most important in your situation.