Outside air for skimmer. Expected results?

[ReefGeezer]

I have two probes and they are calibrated about every 6 months. Over the last several years each has been replaced more than once. Again though this is not an issue for me i resolved this many years ago with an outside air skimmer line. At times i have disconnected the (usually accidently) and the ph starts dropping. In fact when i see low ph the first thing i check is if the airline is still on. The reality is for many people this is a big issue easily fixed with outside air. For many others there is no issue(or there is an issue that outside air wont fix). Just depends on each situation.

I run at a higher than average dkh between 10.5-11.0

Oops, sorry. I thought I was replying to the OP.

 

[kilnakorr]

Oops, sorry. I thought I was replying to the OP.

I rinsed and calibrated the probe before trying anything. Been a victim of ph drifting in the past an all it took was a calibration.
I thought it was an easy test, to hook it up to some outside air, but wanted to adjust expectations before I scratch the idea or make a more permanent solution.
I'll guess I'll let it run a day or two and see if I get a 0.2+ increase.

 

[Crashjack]

True. I've only measured a 0.05 drop in alk in a week. Not sure I can dose that little, and if it would have any effect.
I'm in progress of switching salt, so my alk should increase slowly with waterchanges which should also help in the long run.

You can dose as little as you want. I typically run my kalk 34 seconds every hour (that is with also running a Ca reactor 24/7). This keeps my alk in the mid 8's dkh range. You could start at 5 seconds per hour or less (e.g. less time or spread doses further apart) and see what it does. Assuming you keep adding corals or the ones you have grow, you will eventually need to supplement alk and Ca anyway so you haven't lost anything by starting to dose kalk now.

Kalk increases pH because it removes CO2 from the water. My problem with outside air is that though it can definitely work, that assumes you are pulling in enough outside air to make a difference. For instance, if you were relying on a 100' run of 1/4" airline tubing to access outside air, it is very likely you wouldn't see positive results. However, if you were relying on a 5' run of 6" pvc to access outside air, then you would be almost guaranteed to see results. To me, trying to utilize outside air is somewhat of a pig-in-a-poke. Kalk or even a CO2 scrubber seems to be a lot more of a sure thing.

 

[ReefGeezer]

I rinsed and calibrated the probe before trying anything. Been a victim of ph drifting in the past an all it took was a calibration.
I thought it was an easy test, to hook it up to some outside air, but wanted to adjust expectations before I scratch the idea or make a more permanent solution.
I'll guess I'll let it run a day or two and see if I get a 0.2+ increase.

7.5 seems unusually low @ normal salinity levels (35ppt). That's why I asked about calibration and alkalinity. My post about chasing pH was meant to be more cautionary than prescriptive. Trying to plumb outside air to your skimmer is OK unless it is really cold outside. It works sometimes.

 

[CollectOyster04]

I did the same as you, testing through a window 1st. For me, it made a difference of about .2 or so. I still couldn't justify drilling a hole through the exterior wall so I instead went through the wall but up into the attic. From there I ran the line out of the soffit. Figured it's easier to patch drywall than the brick outside. Have a total of about 30 feet of hose ran and as you walk up to the house you can hear it sucking. Fun to watch people trying to figure out what that noise is when they walk up to the house.
Once you have enough load to justify dosing, you'll be able to have that ph bump as well. I recently switched to Randy's newer formula to give an extra ph bump. Between the fresh air in the skimmer and the dosing regimen I'm currently on, my daytime ph high went from around 8 to now running at about 8.4. For some reference my system is around 300 gallons, currently dosing 85ml/day, and currently using a reef octopus classic 160int with the aquatrance 2000s pump (specs says it pulls 720 lph/25 scfh of air). I'm about ready to start plumbing my reef octopus sro5000xp into the system that uses a dc5500 pump (2,000 lph/ 70 scfh). My own curiosity has me wondering if the extra air from the bigger skimmer will have much more of an impact to my system.

 

[kilnakorr]

I did the same as you, testing through a window 1st. For me, it made a difference of about .2 or so. I still couldn't justify drilling a hole through the exterior wall so I instead went through the wall but up into the attic. From there I ran the line out of the soffit. Figured it's easier to patch drywall than the brick outside. Have a total of about 30 feet of hose ran and as you walk up to the house you can hear it sucking. Fun to watch people trying to figure out what that noise is when they walk up to the house.
Once you have enough load to justify dosing, you'll be able to have that ph bump as well. I recently switched to Randy's newer formula to give an extra ph bump. Between the fresh air in the skimmer and the dosing regimen I'm currently on, my daytime ph high went from around 8 to now running at about 8.4. For some reference my system is around 300 gallons, currently dosing 85ml/day, and currently using a reef octopus classic 160int with the aquatrance 2000s pump (specs says it pulls 720 lph/25 scfh of air). I'm about ready to start plumbing my reef octopus sro5000xp into the system that uses a dc5500 pump (2,000 lph/ 70 scfh). My own curiosity has me wondering if the extra air from the bigger skimmer will have much more of an impact to my system.

I believe I can make this a permanent solutions without making holes in the house.
My main concern here is the small skimmer might not have any or little impact. I changed a much larger skimmer for a roller filter and smaller skimmer. Sadly my sump won't fit both large skimmer and filter.
I do believe I can raise my ph as I want to raise my kh from currently 8.5 to 9.5 and get my refugium running with cheato.

 

[danzig]

An important question that should be paralleled with OP’s question, would be how new/tight is your home. People with older homes.. say older than 1995 have a lot of air infiltration from the outside. 1995 is just a baseline, as building codes vary state and town but in recent years houses are required to be sealed much better. This is a HUGE factor. If someone with a house from 1960 is saying it isnt helping well it likely did nothing because they already had fresh air from outside. Just a rudimentary example.

 

[gentlefish]

+1 on 0.2 increase. I had better success with Farley Alcalinity dosing for low pH tanks. It’s in the reef chemistry and the pH is over 14. Wear gloves while mixing, if you don’t, the sopy feeling of your hands is dissolving skin.

 

[Mical]

To the OP - I have similar situation here in Minnesota - too cold to open windows and elevated CO2. I typically will add a tsp of kalk to ATOs and also added CO2 scrubbers. You can DIY one fairly cheap and the media isn't expensive. Without scrubbers, in winter my Ph is 7.8-8.0 which is ok, but I like mine higher with LPS & SPS. Added scrubbers and currently I run 8.01 to 8.38 daily.

 

[kilnakorr]

To the OP - I have similar situation here in Minnesota - too cold to open windows and elevated CO2. I typically will add a tsp of kalk to ATOs and also added CO2 scrubbers. You can DIY one fairly cheap and the media isn't expensive. Without scrubbers, in winter my Ph is 7.8-8.0 which is ok, but I like mine higher with LPS & SPS. Added scrubbers and currently I run 8.01 to 8.38 daily.

Fresh air and CO2 scrubber have the same limit: the skimmer.
If the skimmer is small the impact of air through the skimmer won't matter much.

 

[kilnakorr]

+1 on 0.2 increase. I had better success with Farley Alcalinity dosing for low pH tanks. It’s in the reef chemistry and the pH is over 14. Wear gloves while mixing, if you don’t, the sopy feeling of your hands is dissolving skin.

Most of these diy threads here aren't an option as the ingredients cannot be bought here, or only in very small quantities (and you need to be VERY careful with translating the stuff)
However, I can just by some expensive commercial stuff to raise kh and for general dosing.

 

[kilnakorr]

12 hrs of fresh air had no impact.
So it's either not CO2 related, or my skimmer doesn't have much impact.

 

[Greg P]

12 hrs of fresh air had no impact.
So it's either not CO2 related, or my skimmer doesn't have much impact.

Have you tested your house air vs the outside air?

Use an air pump and aerate some tank water (in a container) inside your house with your pH probe for about 1/2 hour. What's the pH?
Then aerate some new tank water outside your house with your pH probe. Probably higher ...
This will tell you if your house air is saturated with CO2 enough so that your skimmer can't keep up.

I use a 3' x 1/2" tube to my skimmer running 540lph air intake and it's enough to keep my tank happy

 

[kilnakorr]

Have you tested your house air vs the outside air?

Use an air pump and aerate some tank water (in a container) inside your house with your pH probe for about 1/2 hour. What's the pH?
Then aerate some new tank water outside your house with your pH probe. Probably higher ...
This will tell you if your house air is saturated with CO2 enough so that your skimmer can't keep up.

I use a 3' x 1/2" tube to my skimmer running 540lph air intake and it's enough to keep my tank happy

I just tried with a cup of tank water outside.
After leaving it outside for roughly 2 hours, with a stir now and then, and matching temperature by placing the cup in warm water outside the ph only increased by 0.06.
A little spring weather is upon us today, so currently airing out the house, which should give me an answer. Might not be CO2 after all.

 

[kilnakorr]

Just to update.
Running outside air through the skimmer had no effect. Airing out the house for an hour had no or very little effect.
I bought a new probe and calibrated both with same solution.
Old probe: 7.77.
New probe: 7.89.

I had 7.89 as lowest point last night and 7.99 as highest during the day. Still a little low, but nothing to worry about.

 

[ReefGeezer]

Just to update.
Running outside air through the skimmer had no effect. Airing out the house for an hour had no or very little effect.
I bought a new probe and calibrated both with same solution.
Old probe: 7.77.
New probe: 7.89.

I had 7.89 as lowest point last night and 7.99 as highest during the day. Still a little low, but nothing to worry about.

Those numbers could be normal. Just in case though, here's some silly questions to ponder.

Are you calibrating with 7.0 & 10.0 Solutions & does the probe show pretty close to the numbers when reinserted into the solution?

Do you have surface area turbulence or turn over to encourage gas exchange occurs?

Could there be some excess organic decomposition occurring?

Is alkalinity, calcium, or magnesium low? (CO2 is one side of the equation. Simply stated, its interaction with these elements determine the pH level.)

 

[kilnakorr]

Those numbers could be normal. Just in case though, here's some silly questions to ponder.

Are you calibrating with 7.0 & 10.0 Solutions & does the probe show pretty close to the numbers when reinserted into the solution?

Yes. And shows correct when reinserted into buffer solutions.

Do you have surface area turbulence or turn over to encourage gas exchange occurs?

Open tank with plenty of surface agitation.

Could there be some excess organic decomposition occurring?

Hard to tell, but no ammonia or nitrite. Nitrate same as always 2-3ppm

Is alkalinity, calcium, or magnesium low? (CO2 is one side of the equation. Simply stated, its interaction with these elements determine the pH level.)

All tested. Magnesium a bit low at 1270, but slowly rising from 1200. Alk 8.7, Ca: 470

 

[TbSaysNo]

Did this because my PH was 7.7. After 2 days of skimmer pulling Air from outside, my pH is still 7.7 My alkalinity is 8.3… What to do ?

 

[Spicy Reef]

If it was my house I would drill the hole. That being said, I work construction for a living. It's no skin off my back to rip out some sheetrock and repair an electric mishap or plumping nightmare...
If this is a concern get a long hose and find a hole or crack somewhere, under a door, through a vent (oven, dryer, attic, basement). In all the homes i've worked on, I've never come across one that didn't have a way out.
Someone will correct me if I'm wrong, but I don't think the diameter of the hose has to be that big. Air unlike liquid will put up very little resistance for what we're doing here.

 

[Spicy Reef]

Did this because my PH was 7.7. After 2 days of skimmer pulling Air from outside, my pH is still 7.7 My alkalinity is 8.3… What to do ?

This just toggled my memory. Randy recently posed an experiment. I can't find the post, he was answering this question by asking the inquirer to test the water directly in the tank and then take a sample of the same water, put it outside for a couple of hours see what the ph is. I can't remember if he said to run an airstone in there an maybe even a heater to keep the water at the same temp???
this might be easier as a test than drilling the hole