Not necessarily. You could be adding bicarbonates that would raise KH. A full list of what you dose would reveal this. Things in your tank (substrate, rocks, etc.) could be increasing KH as a function of pH changes and, lastly, BB will consume bicarbonates. So, it is best to identify your tanks' KH, then take a sample and let it sit out. When you measure your sample, a few days later, and compare the pH levels, be sure to test the tanks' KH level to be sure that it matches the KH that existed when you took the tank sample. The KH in my tank will drop throughout the week.
I run my CO2 24/7 and see no significant change in pH, night or day. There are some plants (CAM) that utilize CO2 in the dark (they don't all use O2 at night). So, I let CO2 run day and night to benefit my Dwarf Sag (a CAM plant) and to maintain pH at a stable level below 7.0 (I don't want to risk my ammonium turning into ammonia). I also have noted that running CO2 24/7 uses less total CO2 to maintain the same CO2 level. As soon as ambient light enters the room in the AM, plants can begin photosynthesis. Having said all of this, I've also run on a timer and see no large difference between the two in plant performance but, since I use less CO2 with 24/7 and the other issues, I see no reason to revert to timing the CO2 - nature doesn't do it.
Apologies for the delay, Deanna. Thank's for the input. I didn't know some plants consume co2 at night! Would be nice for me if the dwarf sag grew slower, it's sending out runners all over the place hahaha.
So I did the Ph/Kh comparison and there was no difference. Aged tank water Kh remained the same. Now, the Ph is slightly lower than I thought. I've started using the brightest area in the house near a large window to read the results and there is a difference compared to the spot I used to use. So it's about 7.4, not 7.6. I've been off on all my api tests by a bit for years before this new spot.
I've set the co2 at 1 bps and ph drops to about 7.0. So I'm at 15ppm according to the chart. I'm very happy with how things are going. The plants are growing fuller and bigger. Also noticing quite an increase in nutrient uptake so I'm now dosing PPS Pro along with modified EI because I do 10% weekly w/c.
At the moment I'm dosing:
-API Leaf Zone for daily PPS level K and Fe
-Tropica Premium for daily traces (one squirt, K and Fe very low on this)
-Seachem Flourish Potassium (a little added to new water on w/c to have a base level of 20ppm)
-Seachem Flourish Phosphorus. I don't dose this much because my tap water contains 1ppm already. I dose it to bring my level up to 3 or 4ppm and just leave it, testing weekly. When it drops to around 2, I dose again.
-Seachem Flourish Nitrogen. Same way as P. I dose this to bring nitrates up to the high 30's. Whenever it falls below 20, I dose again.
I have many unopened bottles of these liquid ferts. When I run out I will probably order dry ferts from GLA.
I'm okay with the co2 being off at night because the difference for me is only a 0.4 swing in ph.
I thought I'm saving co2 with it off at night? My bubble rate is a constant 1 bps and doesn't change. Are you using a controller for your co2? I'm trying to figure out how you use less co2 running it 24/7. I only know the basics for pressurized equipments.
Can you write a simple explanation so I can understand it better?
One thing I do in my tank at night I have two air stones at each end of the tank and I run them during the hours of darkness (the 12 hours my lights are off.) that works just fine for my plants and fish. I run an Emperor 400 and the old Marineland H.O.T. Magnum filter in the tank. The Magnum has an adjustable water diffuser which at night I rotate 180* so that the surface of the water is agitated during those 12 hours of darkness. If you monitor your pH at nights it should be a slight higher than during the day. But like I said the two air stones make a big difference and I have them hooked up to an air manifold with adjustable valves to control the flow. Each line has a one way check valve on the event of water being syphon into the lines when the air pressure subsided or in the event of a pump failure.
You can just see the air line with the stone on the corner of the tank.
That's tank looks super! I love tanks with large swords. Is it the camera or is your lighting fairly dim? I've always liked dim lighting and prefer it 99% of the time.
Yup, my Ph goes up at night. For me it's a 0.4 swing. Are you running your co2 24/7?