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Inlet Surface Skimmer from Hinterfeld - Flow Reduction?


9 Jul 2007
Hi Guys,

I've just added a glass surface skimmer inlet to my Eheim Pro e3 700 (1850LPH) and I've noticed that there's a reduced flow since adding it. I've got the skimmer taking most of its water in from the bottom of the inlet however I'm getting relatively frequent burps from the filter. I've no idea where this air is getting in the filter as i can see that there's no air being pulled in from the top of the skimmer. CO2 is on the outlet of the filter so its certainly not that.

Has anyone experienced anything similar with such a device? I was wondering if the in flow us being restricted somewhere as I can clearly hear trickling water inside the filter.

Sorry, are you sure the filter is fully primed? Happens for me every time I have the filter disconnected :confused:. Try a few (or more ;)) hard presses on the prime button.
By the way: I ordered a glass surface skimmer from Hinterfeld as well. But I never used it - after reading a number of threads here at ukaps, I instead added a small air pump that I run at night. I have no oil film at all after that, and I avoided the not so nice looking skimmer inlet ;)
So I've figured the issue but not figured how to resolve it. I have a Juwel Rio 180 and the water line sits a lot lower on the glass than a rimless tank as it has an upper surround. The issue is that the floating part of the inlet is not floating high enough and is blocking the water flow to the inlet as you can see below:

Untitled by Lee Parsons, on Flickr

What it should look like if it was floating high enough is like this (This drastically increases flow rate in this position however I am actually holding the floating part way above the water line:
Untitled by Lee Parsons, on Flickr

I'm not sure how to approach the fix. The floating part is plastic and could be cut down however as you can see, if i cut it down I'm on the boarder of sucking air into the filter. The bottom part of the inlet is totally open so i cant adjust it any more. The only thing I could do from the bottom is to cut more slits in the inlet but ive no experience of cutting glass.

Any advice?
The plastic tube that fits inside the glass, Can you not cut a couple of inches off this to stop it overlapping the intake pipe? Would be the same as the skimmer floating higher.
I have one of these that i plan on installing at the weekend.
EDIT Just measured mine against the outside of the glass,Looks like im going to have to do the same.
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Glad you got it sorted. I'm a bit concerned as these are retailing for £15 at the mo. Seems far to cheep considering the horrible green plastic ones £25.
What spray bar is that your using please
Gass build up in the cannister can have several causes doesn't mean it needs to be physicaly sucked in from the atmosphere. If you add co2, you may have micro bubbles of co2 in the water column, plants metabolise and create microbubbles of oxygen released into the water column during the light cycle. In the filter house farting bacteria etc. The canister is the most likely place for these gasses to deplete and accumulate in it at the highest point. If the canister doesnt stand 100% level it collects a gasbubble releasing a blob over the edge every time it gets to much.

I experienced regular burbs without a skimmer installed.. In my case i had the filter hoses to long pulling and pushing and tilting the cannister sideways.. Tank is standing on a table with the canister in a cabinet next to it. Making the route the water has to take in a closed circuit to the filter and back rather long. The longer this route is the more bends it has, the more microbubbles will deplete from the water into the canisters media, obviously. I took the canister out of the cabinet and placed it directly under the tank and made the hoses as short and straight as possible. Resulting in much less burbs.. Actualy this tank ran out of co2 about 3 months ago and it is back to low tech again all this time. And never heard a burb again since. Kinda adds up with the theory, what you don't put in can't get out.. :)

Summary of the 3 most obvious causes.
Check if the canister stands level.
Make both hoses as short and straight as possible.
Maybe you need a beter diffusing co2 diffuser.
I used one of these for around 6 to 8 months on my previous tank no issues. The only thing i had to do was cut about a inch or so off the plastic insert pipe on the skimmer float part. It would float higher on a braceless tank. If your tank is braced the water level is lower so you have to cut the pipe as discribed above.
For the money cant fault it really.
I stopped using mine as it would regulary take too much air into the filter and then in turn it would suck the flowpipe downwards causingit to stick underwater! Several poor fish got sucked in!
Yes you have to turn the flow control on the bottom of the glass inlet to balance the flow between the underwater inlet and surface inlet to get it to work properly.
Reading all this, makes me look at my sump an smile from ear to ear..... :woot:
Once we move house next month. Looking at getting a aquascaper 600. Can get a ea 600 reef with a sump(same tank with a sump) for a few quid more. But the reef ones only come with black silicone the auascaper has clear or i would deff get the sumped version not the aquascaper.