What the heck is wrong with my skimmer?

[Miami Reef]

It was first producing very dry skimming, but now it’s super wet. I’ve been trying to adjust it because it was only reaching the middle of the neck. I turned it by a hair and it’s fluctuating a lot. Also you can see it’s overflowing then draining back into the tank. This tube leads back to the tank. The overflow tube is on the top of the skimmer. I’ve wondered how the heck my skimmer will take out junk if it’s just going to drain back into the tank.

Also, is the skimmer too wet?

 

[mitch91175]

What type of skimmer is it and do you know the manufacturer suggested water height it should sit in? That's the first place to look is to make sure that you have it in the suggested water level. Then do your adjustments from there. When my skimmer acts up (which they all do at some point), it usually relates to me doing something to my tank, i.e changing filter socks or feeding certain types of food, etc.

If you haven't had the skimmer for a while, you will get to learn those nuances and work around them.

 

[Daniel Waters]

If the skimmer was skimming dry before and is now going crazy overflowing, most likely you have something in the water that has caused this. Typical culprits might be use of epoxy, changing the filter sock to a new one, or some other chemical such as lotion or soap on your hands that went into the tank. If your skimmer has a drain tube, let it drain into a 5 gallon bucket outside the sump. You may have to wind up pulling out several gallons of water, which you can replace with fresh salt water (turn your auto top off during this time if you're using one). Eventually the skimmer will pull out the agent driving it crazy. Also, you can let it just drain back into the sump, and it may get less severe after a few hours. Some things might make the skimmer go crazy for a day or longer, though. And, of course, this is not the preferred method, as the irritant isn't being readily removed from the system if it keeps dumping back into the tank. A short term fix would be to adjust your skimmer height or adjust the air inflow accordingly to make it skim less wet.

 

[Miami Reef]

But is the drain in the bottom of the cup normal? Won’t the garbage just get drained out back in the tank?

 

[mattgsa]

But is the drain in the bottom of the cup normal? Won’t the garbage just get drained out back in the tank?

The drain is normally run to a separate container. Here is an example of a commercial one.
https://www.bulkreefsupply.com/reef-octopus-4-waste-collector-with-auto-shut-off.html

 

[Daniel Waters]

But is the drain in the bottom of the cup normal? Won’t the garbage just get drained out back in the tank?

Where is your drain line on your skimmer cup going now? It needs to go to a collection area outside the tank. You had to be doing it that way before unless you capped off the drain line or drain hole and just collect skimmate in the small cup area...which is perfectly fine to have the drain hole plugged, but you run into these overflow issues like you're experiencing now.

By the way, if you run your skimmer drain line to an container outside your sump, you do have to worry about your skimmer acting up and pulling out several gallons of water and causing all sorts of issues (such as ATO dumping in too much fresh water, sump draining down and pumps running dry). It's good to have some sort of check mechanism or sensor if you set up your skimmer to drain like this.

 

[Daniel Waters]

Also you can see it’s overflowing then draining back into the tank. This tube leads back to the tank. The overflow tube is on the top of the skimmer. I’ve wondered how the heck my skimmer will take out junk if it’s just going to drain back into the tank.

I do not see two tubes on your skimmer in the video. I see the tube in the bottom of your skimmer cup that is draining the skimmate / water. If that is your drain line, it should not dump back into the sump. If that line is some overflow line, then it would drain back into the sump, but that line should be connected up top, not the bottom of the collection cup (and I've never seen a collection cup with an emergency drain line but it's certainly possible to design it that way)