Skimmer overflowed into tank, how much damage does it cause?

reef’r · 2026-09-07T21:30:32-0400

Was out of the house today for several hours and when I got home I noticed a strange smell. Looked around and found my skimmer had overflowed. Definitely dumper skim mate into the tank, should I be super worried and perform water changes? Or is it really not that big of a deal and can do a water change tomorrow? I’ve seen people freak out over this and others say the only thing they notice is an increase in polyp extension lol

WhatCouldGoWrong71 · 2026-09-07T21:33:59-0400

I have done that a dozen times. I actually looked for better extension a couple times at night. For me it depends. If it is normal climate, I do nothing. If I was trying to stretch it out and I put some super badly thick ****, I might wet skim out 5 gallons. But I do that weekly also so.

reef’r · 2026-09-07T21:36:32-0400

WhatCouldGoWrong71 said:
I have done that a dozen times. I actually looked for better extension a couple times at night. For me it depends. If it is normal climate, I do nothing. If I was trying to stretch it out and I put some super badly thick ****, I might wet skim out 5 gallons. But I do that weekly also so.

Okay I don’t have any saltwater ready to go so I guess I’ll just wait until tomorrow. Fingers crossed

Mr. Mojo Rising · 2026-09-07T21:42:38-0400

I’ve done it too, I wouldn’t worry about it your tank will be fine. the skimmer will skim it back out soon.

ptrusk · 2026-09-07T21:43:39-0400

Don't worry about it. Dial in your skimmer.

1. Open Wedge Pipe or Gate Valve: Set the wedge pipe or gate valve to open fully. For a wedge pipe, this generally means lining up the adjustment knob arrow to arrow, and for a gate valve, this means opening it up as much as it will go.

2. Adjust Pump Speed: If you have a speed-controllable pump, turn it to 100%. (Pump speed control would likely be on a controller)

3. Adjust Air Intake: Completely close the air valve and then slowly open it, keeping a close watch on the level of the foam and bubbles inside the skimmer body. The smaller the air bubble, the better. Continue making minor changes to the air valve until you get the absolute peak height of the bubbles in your skimmer body. This will generally take 5-10 minutes to complete, as you will want to wait at least 30-60 seconds between adjustments.

Although it may seem counter-intuitive, closing the air valve decreases the size of the bubbles and increases the amount of air entering the skimmer’s body. This occurs because the pump speeds up when the airflow is restricted, pulling in more air than when the valve is fully open.

4. Adjust Water Level: Slowly turn the wedge pipe valve or gate valve to reduce the amount of water exiting the skimmer body. This will force the water to rise higher in the skimmer’s body. Stop when the bubbles start to reach the bottom of the collection cup/neck of the skimmer, as shown in the image below.

5. Be Patient: Wait 1-2 minutes, and then, if needed, make an additional adjustment to keep the bubbles near the bottom of the collection cup/neck of the skimmer. After 15-30 minutes, you should begin to see larger bubbles forming at the top of the bubble column/foam head.

6. Monitor: After 1-2 hours, the bubble column should naturally rise so that the bubbles are surging up and over into the collection cup. During regular operation, the bubble column/foam head will surge up and down naturally.

7. Check Skimmate: If the waste in your collection cup is very light-colored, open the wedge pipe or gate valve slightly to lower the water level. However, if you barely collect anything, you will want to close the wedge pipe or gate valve slightly to push more bubbles into the collection cup. The goal is to collect brown waste, similar to that of dark-brewed tea.

exnisstech · 2026-09-07T22:16:45-0400

Stuff in my tank loves it when the skimmer overflows. Once shortly after it happened my rocks flowers spawned and coral always show a feeding response.