What ph swing is too large?

[jimmypencil]

My daily ph swing is .5+ and I’m not sure if I should take action to reduce the swing. I dose kalk and AFR 24/7 and I use a co2 scrubber.

@Randy Holmes-Farley I know you gave my exact scenario as an example in your article about ph (a swing of 8 - 8.5 is better than a ph that’s stable below 7.9) but is this a less than desirable swing?

Between Kalkwasser (6.5L) and AFR (110ml) I’m dosing basically 3dkh a day which I feel is a bit high… is it because ph is so high it’s just causing precipitation? I’m at the limit for kalkwasser because of my evaporation rate, and the max daily dose of AFR in my tank is 125ml and I’m already at 110ml. I feel like something isn’t right.

• Should I dose kalk only at night to lower swing? Any other tips to lower the swing?
• Does my daily dkh consumption make sense or is it likely a lot of precipitation?

 

[exnisstech]

Can't help other than to say looking at the tank I'm not sure I would change anything. It's pretty awesome.

 

[Uncle99]

That swing looks normal assuming the measure is actually correct.
Hard to get a consistent long term result on PH.
Tank looks like it’s very happy……which is the most accurate test of all.

 

[X-37B]

Mine goes from 7.9-8.3, night/day.
I have never had a system that does not swing, just like the ocean.

Your system is just a little higher than the oceans swing but not much, 7.9-8.4 From the pic its obviously working.

 

[mfinn]

Years ago I used to test everything and it bugged me that the ph had those night and day swings.
I talked with everybody about it until one friend asked me what I thought was wrong inside the tank. There really wasn't anything I could see. He told me that it was normal and to stop worrying about numbers. Don't try and fix something that wasn't broke.

 

[Randy Holmes-Farley Verified Community Expert]

I’m not sure there is any swing that is too much. I’d look more to the absolute lows and highs.

That said, more aeration will reduce the swing, and perfect aeration will eliminate it.

It’s evidence that the oft stated idea that “I have plenty of aeration” is possibly true, but it is almost never true that aeration is complete.

 

[KrisReef]

It’s a good question, which I don’t have real data for-so I asked the question of Google AI -which is also not real data, but it’s interesting:

AI Overview

On Pacific coral reefs, seawater pH naturally swings in a daily (diel) cycle of more than 0.2 to 0.7 units driven by biological metabolism and sunlight. [1, 2, 3]

———
GAI says that you have nothing to worry about.

 

[jimmypencil]

Thank you everyone. I agree I don’t want to change anything since there’s no real issue currently.

I guess my main concern is how much I need to dose to keep up with alk. 3dkh seems excessive and idk if I have enough large colonies to justify that consumption. Thats why I assumed there may be some precipitation which is making me dose an artificially large amount.

@Randy Holmes-Farley any thoughts on the alk consumption? Like I said I’m basically at the limit for kalkwasser and AFR, I would be surprised if I also have to use soda ash with the aqua wiz given that my tank is not totally overgrown with large colonies.

Maybe it’s because I have plague levels of vermatid snails? I have virtually ZERO coraline for some reason.

 

[X-37B]

You have some large plating corals in there. Useage will just increase as the system grows.
Consider a carx. I run one with kalk on my 150.

 

[Randy Holmes-Farley Verified Community Expert]

Thank you everyone. I agree I don’t want to change anything since there’s no real issue currently.

I guess my main concern is how much I need to dose to keep up with alk. 3dkh seems excessive and idk if I have enough large colonies to justify that consumption. Thats why I assumed there may be some precipitation which is making me dose an artificially large amount.

@Randy Holmes-Farley any thoughts on the alk consumption? Like I said I’m basically at the limit for kalkwasser and AFR, I would be surprised if I also have to use soda ash with the aqua wiz given that my tank is not totally overgrown with large colonies.

Maybe it’s because I have plague levels of vermatid snails? I have virtually ZERO coraline for some reason.

If there is any significant precipitation, it's likely happening during the peak daily pH high. Do you see any signs of it, such as hardening sand or excessive precipitation on pump impellers?