Help, I Think My Filter Is Clogging

[Boulder Fish]

I have a 20 gallon tank with a HOB filter. I was doing my regular cleaning/partial water change, about a week late. There is more green algae built up than usual, and I noticed the flow coming out of my filter was diminished a little. I took the uptake mechanism out to check for a clog, but it looked clear. The filter bag (which is filled with ceramic rings) however is pretty dirty. I lifted it up to take a quick look and then replaced it and turned the unit back on. That is when I noticed the back flow on the uptake side.

I am very nervous about cleaning the filter bag, as I had a horrible experience in the past with killing my bacterial colony. Everything has been going so well in this tank. I had a flawless fishless cycle, and added 10 celestial pearl danios and 3 chain loaches about 3 months ago. They have all been very happy and healthy. I do not want to do anything to jeopardize what has been a great start to this tank. HELP.

Thanks.

 

[fatheadminnow]

What kind of HOB do you have?

Over time, debris and what not get stuck in the bottom of your filter, causing the flow rate to decrease.

When the water flowed back out through the intake pipe, was it all of a sudden, or was it when you turned the filter back on?

If it was all of a sudden, this is because of the vacuum created when the filter is on.

Think of it this way. When you gravel vac your substrate with a syphon, and than you take the end of the syphon hose, the end not in the tank, while water is still in it, and raise it to the same level of the water in the tank, usually the water in the hose will rush back into the tank.

What is happening with your filter is, when you removed the bag of ceramics, the water level dropped in the filter, the water level in the filter dropped below the water level in the tank.

When this happened, since the water level in the filter is lower than the water level in the tank, there is going to be a greater amount of pressure (atm) on the lower level of water in your filter, than there is in the tank.

This greater pressure, is going to push down on the water in the filter, and since the only place for the water to go is out back in to the tank through the inlet, this is where is goes.

Nothing to be alarmed with.

Next time you take your filter media out, either through it right into your tank so it won't dry out, or place it in a bucket of tank water that you have removed form the tank.

-FHM

 

[Boulder Fish]

Thanks for your response. It did happen just after I turned the filter back on. I am a lot less worried now that a couple of hours have passed. The water has cleared quickly, so I am confident I am still getting good filtration. The flow seems to have returned to normal.

I have read on numerous posts that many people never touch their filter bags. Until I saw the diminished flow, it was my intention to "leave well enough alone." And, now that it looks like its back to normal, I probably will. If this becomes a problem later, what is the best way to clear away some of the gunk that may be causing that decrease in out flow? Do I just shake the bag around in the bucket of tank water? I have a Top Fin 20 HOB filter with a simple "floss" bag insert which I have PACKED with ceramic rings.

 

[Mikaila31]

To clean the media, just use a bucket and some tank water. Shake it around, squeeze it with your hands, whatever works best to get the debris out.

Also you may want to take a look at filter body as well. Mainly the impeller, the little thing that spins around in the filter. It is magnetic and should pull right out of its hole. Clean and debris off the impeller and clean the hole it was in as well. You will often get a build up of debris there, it slows down the impeller and reduces the flow over time.

 

[Boulder Fish]

Thank you for your response. I will do that this weekend.