Large drop in pH

[RobZilla04]

Gotchya. The only point I am trying to make is that the skimmer and air stone are both going to be pulling the same CO2 filled apartment air into the system. Neither is going to "provide" more O2 than the other (unless you run an intake line to a place where the O2 content is greater such as outside).

Best of luck.

 

[Reef of Fillory]

Gotchya. The only point I am trying to make is that the skimmer and air stone are both going to be pulling the same CO2 filled apartment air into the system. Neither is going to "provide" more O2 than the other (unless you run an intake line to a place where the O2 content is greater such as outside).

Best of luck.

Thanks for the feedback,

I am going to be running the input through a TLF reactor filled with CO2 scrubber media

 

[120reefkeeper]

I am pretty sure that the CO2 levels in my apartment are so high that it might not be beneficial to have greater O2 exchange, as it may lower my pH even further. I had thought about the air stone idea, but i've never used one, and from what i've heard about using them, they make a good deal of noise, and also "make a mess".

The way that the "sump" area in the Fluval EVO works doesn't give me much confidence that i'd be able to prevent bubbles from anything making it back into the tank.

I use a DIY media rack with filter floss on top and Chemipure Elite underneath that, then the water goes diagonally to the second chamber which then flows right over to the third chamber with the pump. There isn't a good place to put a foam block or anything like that to stop bubbles, unfortunately.

This guy @120reefkeeper drilled out a bucket and put an air pump + air stone to his sump and saw a pH improvement though, so if I can find a way to deal with bubbles, that might work.

https://www.reef2reef.com/threads/low-ph-issues-make-your-own-co2-scrubber.271306/

I did order the skimmer off of Amazon, so I may be able to just run it with the air intake plumbed to my TLF reactor and call it good. I'd rather not run a skimmer, but if that's what it takes, then that's what's i'm going to do.

I put the wooden air stones from the bucket and ran the lines into my filter socks... the water boils feverishly inside the socks... no bubbles escape.

 

[Reef of Fillory]

I put the wooden air stones from the bucket and ran the lines into my filter socks... the water boils feverishly inside the socks... no bubbles escape.

I wish they made very small filter socks! My drain section is 3" x 3"

If it wasn't so much work, I'd try to fabricate some sort of holder and make my own socks

 

[Reef of Fillory]

I put the wooden air stones from the bucket and ran the lines into my filter socks... the water boils feverishly inside the socks... no bubbles escape.

Does it make a lot of noise? My tank is an All-in-one 13.5 gallon, so I don't have a cabinet/sump to hide the sound

I found these, which might work: https://www.marinedepot.com/Innovat...-ANcYZWmdgcBgcQbjutu8bZDRXNXHsp0aAocNEALw_wcB


Throw my ChemiPure Elite and air stone in there and call it good on the skimmer

 

[120reefkeeper]

Does it make a lot of noise? My tank is an All-in-one 13.5 gallon, so I don't have a cabinet/sump to hide the sound

Nope it’s very quiet.

 

[Randy Holmes-Farley Verified Community Expert]

Just a reminder to everyone reading, pH is totally unrelated to O2 levels. I think some of the folks above know that and are just using the term sloppily, but some readers may misunderstand.

 

[alex.mccann99]

Are you Carbon Dosing the tank at all? I have been Carbon Dosing my tank (Vodka) for years. I overdosed it about a week ago (accidentally turned on my doser for 30 minutes instead of 3), I got a huge Bacteria Bloom. My pH plummeted down to 7.3. I did a massive water change and siphoned all the slimmy bacteria out of my sump. My pH immediately improved, now that the bacteria wasn't eating up the oxygen supply. I ended up leaving my Carbon Dosing turned off and have seen a nice improvement on my tank's pH. It's sitting comfortable between 8.0 to 8.2 every day now, where as before it struggled to maintain anything above 8.0. Just thought I'd share, but it could be linked to bacteria coming and going from your water column.

 

[alex.mccann99]

pH and Oxygen is totally related. Simple proof, when I open my window next to my tank I easily see a .2 improvement to pH within a couple hours of opening it. Same goes to people that run an airtube to their skimmer from the outside.

 

[Reef of Fillory]

Are you Carbon Dosing the tank at all? I have been Carbon Dosing my tank (Vodka) for years. I overdosed it about a week ago (accidentally turned on my doser for 30 minutes instead of 3), I got a huge Bacteria Bloom. My pH plummeted down to 7.3. I did a massive water change and siphoned all the slimmy bacteria out of my sump. My pH immediately improved, now that the bacteria wasn't eating up the oxygen supply. I ended up leaving my Carbon Dosing turned off and have seen a nice improvement on my tank's pH. It's sitting comfortable between 8.0 to 8.2 every day now, where as before it struggled to maintain anything above 8.0. Just thought I'd share, but it could be linked to bacteria coming and going from your water column.

I'm not carbon dosing

pH and Oxygen is totally related. Simple proof, when I open my window next to my tank I easily see a .2 improvement to pH within a couple hours of opening it. Same goes to people that run an airtube to their skimmer from the outside.

The reason that you see a pH bump is because the air coming from outside has less CO2 in it, and the equilibrium is shifted between the tank and the surrounding air. It's the CO2 level that affects the pH, not the Oxygen level

 

[salty joe]

Evaporating so much water that replacing it with full strength kalk raises alk too high, is not a bad problem to have.

IMO, the simplest, most effective and cheapest remedy to your low pH is to dose enough full strength kalk to maintain alk. Then, make up the difference in evaporated water with RO/DI.

 

[Randy Holmes-Farley Verified Community Expert]

pH and Oxygen is totally related. Simple proof, when I open my window next to my tank I easily see a .2 improvement to pH within a couple hours of opening it. Same goes to people that run an airtube to their skimmer from the outside.

That first sentence is simply not true. Your observation is certainly correct, but the conclusion you draw is not.

pH is ONLY determined by the CO2 level. Reef tanks can have any combination of high/low O2 and high/low CO2. It is jus tthe high/low CO2 that impacts pH.

 

[RobZilla04]

Just a reminder to everyone reading, pH is totally unrelated to O2 levels. I think some of the folks above know that and are just using the term sloppily, but some readers may misunderstand.

Can we assume that increased O2 exchange effects CO2 in a way that is benefictial to (increases) pH?

 

[ksfulk]

Depending on how close your tank is to a window, you can use a Toms aqualifter pump/freshwater air pump and run flexible airline out of the apartment and "pull" air from outside and into the tank with an airstone or something similar. In the winter, my tank runs at a relatively low pH (~7.7) even with an outside air draw, kalk in the top off water and a tumultuous water flow at the water line for gas exchange. With the tank volume being small, that could be the fix that works for your size, without having to run a HOB skimmer, which will simply recirculate the apartment air. Its a $20 fix, if it works well enough.

 

[Randy Holmes-Farley Verified Community Expert]

Can we assume that increased O2 exchange effects CO2 in a way that is benefictial to (increases) pH?

No. High CO2 indoor air can have almost exactly normal levels of O2. Such aeration may increase both in the aquarium.

 

[RobZilla04]

No. High CO2 indoor air can have almost exactly normal levels of O2. Such aeration may increase both in the aquarium.

So the benefit of pulling outside air into the aquarium setting (provided the outside air has less CO2 content) is for lower the CO2 content than the inside ambient air?

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, this Reef Chemistry Question of the Day focuses on how little O2 changes indoors when CO2 can change a lot (percentage wise):

Reef Chemistry Question of the Day #240 Conversion of CO2 to O2
https://www.reef2reef.com/threads/r...f-the-day-240-conversion-of-co2-to-o2.332225/

 

[Randy Holmes-Farley Verified Community Expert]

So the benefit of pulling outside air into the aquarium setting is for lower CO2 content than the current ambient air?

yes.

 

[Reef of Fillory]

Depending on how close your tank is to a window, you can use a Toms aqualifter pump/freshwater air pump and run flexible airline out of the apartment and "pull" air from outside and into the tank with an airstone or something similar. In the winter, my tank runs at a relatively low pH (~7.7) even with an outside air draw, kalk in the top off water and a tumultuous water flow at the water line for gas exchange. With the tank volume being small, that could be the fix that works for your size, without having to run a HOB skimmer, which will simply recirculate the apartment air. Its a $20 fix, if it works well enough.

The skimmer is actually one that fits in the back chamber of the tank, and I already have around 40 lbs of scrubber media from my previous tank. I'm going to use a spare TLK phosban 150 reactor to feed the skimmer air input, and simply let the skimmer run without collecting anything [probably have it drain back in to the tank].

Tests last night show 0.00 phosphate and 0 nitrate, so I'm not wanting to use the skimmer for any reason other than introducing the scrubbed air. I was unsure about the possible salt creep/mess that might be made in the back chambers if I went with an air stone and air pump, so that's why I opted for the skimmer instead as i've used that method in the past.

I have thought about running the input from the CO2 scrubber outside though to lengthen the scrubber media life, but in the past i've tied the scrubber input to the cap of the skimmer cup to make sure humid/moist air was entering, and that increased the media life by more than 4 times.



Side note: the corals are coloring up slowly but surely. I think they need more light, as the higher I turn my Primes, the better they seem to react! I've got my metal halide fixture arriving today or tomorrow, and that along with the skimmer/CO2 scrubber will be the last time I change something on the tank! (because that always works, right?)

 

[grassy_noel]

I think people often think that CO2 and O2 exist in the air in similar concentrations...this couldn't be further from the truth. CO2 at 400 ppm makes up 0.04% of the air. O2 makes up almost 21% of the air. When the CO2 level in a room doubles to ~800 ppm (which will have a profound effect on the pH of your aquarium), assuming all of that CO2 is replacing oxygen, the oxygen level drop is negligible. O2 would drop from ~20.9% of the ambient air to maybe 20.8%. The pH drop in the tank is the result of the formation of Carbonic Acid, which is a product of CO2 dissolved in water.

@Reef of Fillory , maybe it would be helpful to invest in a CO2 monitor for your room. You can get one for less than $100 on Amazon, and it would give you an indication of when the CO2 is getting very high. Maybe when it goes over 700 ppm, for instance, you could open the windows overnight and then close everything back up and start the A/C again in the morning. It may be that your apartment is just built very "tight" and your CO2 is building up over time. If you can open the windows once a day, that might be enough to keep the level from rising so high.

Of course, this will likely raise your utility bills as the humidity swings in your Apt may cause your A/C to run a lot when you re-close the windows...but it might help your pH issue (if the skimmer/scrubber does not).