Air building up under my skimmer base. Is that normal?

Eclyps19 · Dec 6, 2022

Alright, in my journey to figure out why my skimmer is skimming so wet when it's almost entirely out of the water, I noticed that under the base of the skimmer air is being trapped. If I tip the skimmer to the side and let all the air up and then put it back, it will build back up under there over the course of about 15 seconds. I don't see any bubbles around the sides of my skimmer so it's not actually bubbling over, but it's like a small amount of air is being pushed down through the bottom of the base and then circulating with the air in the skimmer. Now, I've never gotten down and looked under a skimmer on a clear stand so I have absolutely no idea if this is normal, but I thought I would ask just in case it's not. Here's a video of the air.

ShepherdReefer · Dec 7, 2022

Mine does the same.

Smithrz · Oct 27, 2023

I’m having the same issue, and it’s causing a burping sound every 30 seconds or so, from when the bubbles build up too much and find their way around the skimmer. It’s definitely sorta leaking larger air pockets under the skimmer base which are then being trapped in the various pockets of the plastic, I got down and looked with a torch and watched the whole process.

I’ve tried varying the pump intensity, and I’ve disassembled and reassembled the skimmer (as this wasn’t happening on day 1, it started on day 2). Neither of these fixed the issue. I’m not sure what else to try… did you find a fix for this??

Smithrz · Oct 28, 2023

Okay, so I think I found a solution (for my setup anyway). See attached images…

1. Don’t force it in as far as it can go so that it’s right against the pump impeller, imagine giving it just a few millimetres of space.

2. Don’t over-tighten, I had previously gone and tightened it as much as I could because I saw a video that said if it was too loose, it would make the skimmer noisy. So I went back and just tightened it a little, hard to describe; but just a solid one-time hand tighten seems fine.

3. Reset the flow dial to fully closer, and slowly ramp up until the bubbles reach the narrowest section of the neck (as it reaches the collection cup).

4. Play with your pump intensity; I found that a higher intensity was better than lower, e.g. 40% was better than 20%.

My hypothesis is that if you over tighten these seals, it means the only place for excess air to go is down through the gaps in the bottom of the base, and allows air to accumulate below too quickly, which causes the burping as they release to the water surface.

I can still see some air formed below now, but it’s not nearly as much, and seems to just be sitting there. Mine has gone from burping every 10 seconds to just every now and again at an irregular cadence, I don’t really notice it now, but i’ll keep monitoring and update this thread if there’s any change.

My next step will be emailing Red Sea support if it gets worse again.

Hope this helps someone else who has the issue.

AIRDADDY · Oct 28, 2023

Smithrz said:
Okay, so I think I found a solution (for my setup anyway). See attached images…

1. Don’t force it in as far as it can go so that it’s right against the pump impeller, imagine giving it just a few millimetres of space.

2. Don’t over-tighten, I had previously gone and tightened it as much as I could because I saw a video that said if it was too loose, it would make the skimmer noisy. So I went back and just tightened it a little, hard to describe; but just a solid one-time hand tighten seems fine.

3. Reset the flow dial to fully closer, and slowly ramp up until the bubbles reach the narrowest section of the neck (as it reaches the collection cup).

4. Play with your pump intensity; I found that a higher intensity was better than lower, e.g. 40% was better than 20%.

My hypothesis is that if you over tighten these seals, it means the only place for excess air to go is down through the gaps in the bottom of the base, and allows air to accumulate below too quickly, which causes the burping as they release to the water surface.

I can still see some air formed below now, but it’s not nearly as much, and seems to just be sitting there. Mine has gone from burping every 10 seconds to just every now and again at an irregular cadence, I don’t really notice it now, but i’ll keep monitoring and update this thread if there’s any change.

My next step will be emailing Red Sea support if it gets worse again.

Hope this helps someone else who has the issue.

Great troubleshooting! I have a similar problem but different skimmer but you have inspired me to get down to the root issue.