Tunze 9011/9016 in sump

[FFalas]

Hi Roger, a while ago i asked you for some help regarding using the 9016 skimmer in a sump. I have both a 9011 and a 9016 (only difference i see is the size of the cup really). I have never managed to get the 9016 working in my sump, i have recently taken out my 9011 from the second tank (where i need plankton to train mandarins for feeding) - where it was working without any facia plate and fully immersed to the water line. I have tried this thiing it will work but this has the same issues.

I have tried two ways:
Immersion: water level is about 25cm. I have attached the bottom plate with the open slats in it and used the facia with the hole cover and cover fully open. After 24hrs the bubbles do not raise above the water line, water comes out of a hole at the back of the skimmer.

Sump: i used the water outlet pipe, connected with the plate fuly open with the additional piece that goes inside it to connect to the circular white intake, i use the bottom plate without any openings closed with the kink to face the front of the skimmer. Water level was a little lower, about 23cm. The water would rise to the very top of the outlet pipe but not overflow, a slight tilt would make the water overflow but i am sure this is not the correct operation.

In both cases the skimmers are placed in the middle chamber and intake draws water from the current passing under a baffle placed next to it. Current is not very strong as return probably delivers 800lph at best. There is another skimmer (rated for 500lts) in the first compartment that works like it should.

I have read the manual over and over, i am sure it should still pick up enough organics to foam. I would love to have your expert opinion before dooming one of the two to permanent storage.

Thanks! F

 

[rvitko]

That is correct the only difference is the cup, the 9016 lets you run the air to maximum capacity.

The immersion level is on the low side, 24-29 cm is recommended at the lower end a 9011 would work OK but fairly dry foam, a 9016 might not perform, raising to 27-29 would help.

Something is wrong if water does not overflow the pipe, usually that will be the bottom lid is slightly open.

The 9015/9016 can be finicky, it needs the maximum air performance to work. When they don't perform I typically find a group of a few small problems rather than a single large one. Issues I have seen cumulatively cause performance issues are as follows, you will generally need at least 500l/hr of air for this model to perform so you can troubleshoot effectively with an air flow meter.

1) Build of sediments in the skimmer body
2) Accumulation of salt in the air line reducing air flow
3) Venturi nozzle/impeller housing part 3130.130 is not perfect, much of this part is hand glued and hand machined and small errors can cost airflow.
4) Air line nipple is not fully inserted or is worn or damaged creating a loss of air suction.
5) Impeller is worn, undersized, for example a 60Hz impeller on a 50Hz pump or a 60Hz impeller which is made by cutting the 50Hz on a lathe and was cut too small.
6) Air hose is kinked or damaged
7) Silencer has a leak.
8) A small piece of debris has clogged the airline, the thread for the air adjustment is cut by hand and occasionally a bit of plastic has been left behind and drawn in to the airline.
9) The impeller is worn so it slips and does not pick up the rotational speed, early eJet pumps can also have a defect where they spin backwards and produce a quarter of the flow they would spinning forward but this is almost unheard of past Jan 2011.

I have worked on a few of these in the last several years almost always it is 3-4 of these and as you solve one you see the airflow edge up, so you may start with 250-300 l/hr and add 50-100 for every issue you solve. You need to get to where the gauge reads 450-500, the gauge has a cost of about 50l/hr if properly connected (Sanders) and the real flow is 50 l/hr more.