pH day to night swings in Nano - Refugium

[Gk5321]

I have a small ~8 gal water volume sps tank that i recently installed a controller on. I’ve been monitoring pH and noticed significant swings between day and night. I know swings are expect but the range is pretty significant - approximately 1 ph or more over the course of a day. I think it would be neat to add a refugium using something like the PhytoTank Macroalgae Chaeto Reactor. I know adding chaeto can bring its own challenges like nutrient stability especially in such a small tank (dropping everything to zero pretty quick). But what I don’t know is how pH reacts to chaeto. I would like to boost pH at night but I wasn’t quite sure what will happen during the day. Will pH swing the same amount but even higher with a refugium? Right now the max I get during the day with the lights on is roughly 8.6. The low at night is ~7.6.
Also, I’m sure it’ll come up about not chasing numbers. Everything is healthy and growing but I’d just like to understand what a refugium would do becuase I plan on having a much larger tank in the future. If I get a refugium and raise the ph at night will the tank then all of a sudden reach a ph of 9 with the lights on?

 

[Enchanted Reefs]

I would stay away from chaeto with such a small tank. Look into dosing kalkwasser at night or running a co2 scrubber during the night to minimize the gap

 

[Randy Holmes-Farley]

How is this tank aerated? It seems deficient.

 

[Gk5321]

How is this tank aerated? It seems deficient.

I wrote this as a bit of a rant, sorry. I should’ve explained more. I have pretty significant surface flow and a skimmer that comes on at night triggered when the pH probe hits 7.95. I tried to DIY a CO2 scrubber but it didn’t want to work correctly. I kind of gave up on the idea before I fully vetted it so I may try that before I go with a refugium or kalkwasser. I use a reefglass nano skimmer and the air pump I’m using refused to push air through the scrubber I made (glass mason jar with an inlet and outlet in the lid). I don’t think it was a flow restriction issue I just think the air pump I have sucks. I’m going to try a new one and see how that goes. I wouldn’t mind doing kalkwasser I’m just a bit nervous about it because I’ve never used it before and the tank is very small so things can fluctuate pretty quickly if I’m not very careful.

 

[Gk5321]

I would stay away from chaeto with such a small tank. Look into dosing kalkwasser at night or running a co2 scrubber during the night to minimize the gap

Thanks for the ideas, I wrote a bit more in my comment above.

 

[Gk5321]

Here is the tank by the way. I forgot to mention it’s outfitted with equipment as if it’s 100 gallons or more

 

[Townes_Van_Camp]

Thanks for the ideas, I wrote a bit more in my comment above.

I've been running a small algae scrubber at night and my skimmer during the day. I haven't recorded the data. But it's been quite effective in regards to stabilizing ph without strippimg the tank of nutrients.