skimmer air intake

[Bigair]

Hello everyone, have any of you connected the intake of your skimmer to a pipe leading outside of the under-tank chamber? I tried searching the forum, but I only found a few people who extended the pipe all the way outside the wall. Two days ago, I allowed fresh air from my home to enter, and I noticed a significant increase in ORP (oxidation-reduction potential). I understand that some might not pay much attention to this parameter, but it likely indicates that the oxygen level has risen to its highest point. As a result my PH also rises a little bit. My assumption is that due to the very close design of the intake and outtake for most skimmers, the air circulates within the chamber, resulting in fewer fresh air exchanges. I'm a bit surprised that no one seems to be discussing or experimenting with this. In fact, it might yield similar results to outdoor piping. What are your thoughts?

 

[WhatCouldGoWrong71]

I run mine outside. For redundancy I also have it go through a CO2 scrubber (my lawn guy will mow up to the window I have the tube sticking through. I have also ran a recirculator, that was instantly pegging the meter, but 1) reading a thread by Randy about 02 ad 2) the fear of my skimmer overflowing (didn't have a flow sensor for my FMM at the time) had me unhook it. But I am able to maintain 8.3 most of the day and 8.2 through the night. But, I was instantly north of 8.3 using a recirc.

 

[Joe31415]

I run mine outside. For redundancy I also have it go through a CO2 scrubber

That's how mine is also, with the addition of a valve that opens when the pH is above 8.3 to draw in air from the immediate area. It's primary purpose is to take the CO2 Scrubber out of the equation when it's not needed so as not to use up the media as fast.

 

[WhatCouldGoWrong71]

That's how mine is also, with the addition of a valve that opens when the pH is above 8.3 to draw in air from the immediate area. It's primary purpose is to take the CO2 Scrubber out of the equation when it's not needed so as not to use up the media as fast.

Apex valve?

 

[exnisstech]

I ran mine up into the attic which is isolated from our living quarters and receives fresh air from ridge and soffit vents. My tank in the bedroom had pH dropping to 7.9 at night and now stays solid at 8.3 even at night with 2 adults and 2 dogs breathing. I can't comment on ORP as I have no idea what it is.

 

[Bigair]

It appears that very few people are interested in this topic, and even fewer are familiar with ORP. Most of the time, people tend to focus on pH levels rather than oxygen levels. This could be one of the reasons why so many individuals encounter issues with cyanobacteria. It's just a hypothesis that requires further investigation to confirm.

 

[exnisstech]

Most of the time, people tend to focus on pH levels rather than oxygen levels

I don't really even focus on pH. I found my Hanna tester under a pile of stuff and figured I would test just for the heck of it. Hadn't tested in years and will probably be years before I test again. I just added the air line to one skimmer because I figure it couldn't hurt even tho the tank has been running in the bedroom for years and I'm sure pH has been dropping at night the entire time.

 

[Randy Holmes-Farley Verified Community Expert]

It appears that very few people are interested in this topic, and even fewer are familiar with ORP. Most of the time, people tend to focus on pH levels rather than oxygen levels. This could be one of the reasons why so many individuals encounter issues with cyanobacteria. It's just a hypothesis that requires further investigation to confirm.

You might get a more detailed discussion of a chemistry topic like this in the chemistry forum.

Many of us are familiar with ORP, and I do not believe it is a useful indicator of O2 levels.

The difference in O2 between indoor air and outdoor air is minimal, even in cases with high indoor Co2.

IMO, if there is a repeatable difference in ORP by messing with the air input of a skimmer, it is most likely dur to changes in the skimming effectiveness/ease of air entry to the skimmer, or to changes in pH, not to changes in O2.

 

[Joe31415]

Apex valve?

pH controller connected to a ball valve.

 

[Troylee]

I ran my skimmer line outside after having low ph problems and it’s still stuck at 7.8-8.01 at best.. it didn’t really make any difference at all maybe got my ph up .03 at best… I’m currently dosing sodium hydroxide slowly and bringing it up… right now it runs 8-8.15 I don’t really bother with orp myself.

 

[Bigair]

You might get a more detailed discussion of a chemistry topic like this in the chemistry forum.

Many of us are familiar with ORP, and I do not believe it is a useful indicator of O2 levels.

The difference in O2 between indoor air and outdoor air is minimal, even in cases with high indoor Co2.

IMO, if there is a repeatable difference in ORP by messing with the air input of a skimmer, it is most likely dur to changes in the skimming effectiveness/ease of air entry to the skimmer, or to changes in pH, not to changes in O2.

Thank you for your response, and I greatly appreciate your article about ORP, I read it some weeks ago. In fact, I just want to clarify a tbd point: placing the protein skimmer in a nearly airtight or poorly ventilated sump is likely not a good practice unless one extend the skimmer's air intake outside the sump cabinet.

Recently, I upgraded my protein skimmer, nearly doubling its size. As a result, my pH increased from the 7.9-8.1 range to the 8.1-8.3 range. I used to use a CO2 scrubber, but now it's completely unnecessary. Additionally, I noticed that my ORP has risen from around 200 to approximately 300 within two weeks of changing the skimmer. When I directed the skimmer's air intake outside the cabinet using a flexible hose, my ORP increased to over 400.

I believe that running a skimmer without extending its air intake with a longer hose is akin to having a car engine without an exhaust pipe, where a significant portion of the exhaust gases is drawn back into the intake air. Based on the parameter changes before and after changing the skimmer, I think the larger skimmer increases the rate of water and air mixing, enhancing oxygen dissolution while expelling carbon dioxide. Consequently, the skimmer's exhaust will have lower oxygen levels compared to the intake, and higher levels of carbon dioxide. This is why I strongly recommend extending the skimmer's air intake outside the sump cabinet. This minor modification can simultaneously elevate both pH and ORP.

What are your thoughts on my understanding of this issue?

 

[reefluvrr]

Recently, I upgraded my protein skimmer, nearly doubling its size. As a result, my pH increased from the 7.9-8.1 range to the 8.1-8.3 range. I used to use a CO2 scrubber, but now it's completely unnecessary. Additionally, I noticed that my ORP has risen from around 200 to approximately 300 within two weeks of changing the skimmer. When I directed the skimmer's air intake outside the cabinet using a flexible hose, my ORP increased to over 400.

Can you share what skimmer did you upgrade from and to? Also what is the size of your tank?
I believe typically ORP and pH are inversely related. Whenever my pH goes down, my ORP goes up.
When you increased your ORP as well as your pH, maybe the new skimmer was able to remove much more organics and increase aeration such that your whole pH and ORP chart shifted to a new equilibrium state? Were there any other changes you did to your tank during that time as well?

 

[Bigair]

Can you share what skimmer did you upgrade from and to? Also what is the size of your tank?
I believe typically ORP and pH are inversely related. Whenever my pH goes down, my ORP goes up.
When you increased your ORP as well as your pH, maybe the new skimmer was able to remove much more organics and increase aeration such that your whole pH and ORP chart shifted to a new equilibrium state? Were there any other changes you did to your tank during that time as well?

my small tank is 48g, upgrade from a Tunz skimmer to Nyos Quantum120, it is indeed that more organics are being removed and quite different as before, and I have a strong conviction my "exhaust pipe theory", isn't it true?

 

[reefluvrr]

have a strong conviction my "exhaust pipe theory", isn't it true?

It is true that you get more oxygen from outside air than CO2. I do not have the luxury of connecting outside air to my skimmer so I cannot answer you from my own experience. Randy has told people to measure their sample of tank water using airstone outside. Maybe you can see what that pH and ORP is outside compared to your tank?

 

[Bigair]

It is true that you get more oxygen from outside air than CO2. I do not have the luxury of connecting outside air to my skimmer so I cannot answer you from my own experience. Randy has told people to measure their sample of tank water using airstone outside. Maybe you can see what that pH and ORP is outside compared to your tank?

not that luxury, you just need a arm long pipe to reach the "outside" of the sum

 

[reefluvrr]

not that luxury, you just need a arm long pipe to reach the "outside" of the sum

My tank is an office tank. Will have to go through other tenants and permission of owners to run line out...

 

[theMeat]

If the co2 level inside is higher than outside you will see a difference if you run the intake from outside. If not you won’t see a change although it will be quieter

 

[Bigair]

only a small change

 

[Joe31415]

If the co2 level inside is higher than outside you will see a difference if you run the intake from outside.

And there's an easy way to figure out if that's a worthwhile thing to do.

Get some tank water and stick an air stone in it for an hour. Check the pH.
Get some new tank water and let it sit outside with an air stone (the pump needs to be outside also) for an hour and check the pH.
If the fresh air raised your pH, it may be worth added line to outside. If it didn't make a difference, it's likely not worth the effort.

 

[Randy Holmes-Farley Verified Community Expert]

One of the complications to any use of a skimmer to raise pH (outside air or scrubber, for example) is that it is fighting against tank top aeration which may be in high CO2 air.

Lowering the indoor CO2 level, if possible, gets at the root of the problem.