No clue about this Tunze 9400--help?

___ · May 21, 2021

Hi there, just got my Tunze 9400 skimmer. At first it was going insane, could not control the amount of aqueous bubbles, it filled up almost instantly, even when the air line all the way clamped. THEN is stopped doing anything...I can fill the pump on, but there's nothing, no bubbles at all, even when the air line open. I opened it up and couldn't find any issues, it's a pretty simple device (other than getting the cover back on). Put it back in the tank and still nada.
I know it needs a "break-in" time, but it's this normal? It has swung a 180 from going super active to nothing. So frustrated.

rvitko · May 21, 2021

Which model do you have? 9410, 9415, 9430? AC or DC?

Usually an issue like this is related to depth or an additive that was used.

___ · May 21, 2021

rvitko said:
Which model do you have? 9410, 9415, 9430? AC or DC?

Usually an issue like this is related to depth or an additive that was used.

Comline doc 9004

rvitko · May 24, 2021

Can I get a photo of how it is installed?

Generally when a skimmer goes from overdrive to nothing the cause is a surfactant additive or the depth of submersion. On a 9004 the water comes in under the cup, 1/4-1/2 of this inlet grate must be submerged. If too little is submerged it has free access to atmospheric air so the air adjustment does nothing, at the same time it is starved for water. Any colloidal additive, phenols from filter material, dechlorinators, biological additives, medication, etc, will tend to act as a surfactant, i.e. it changes the surface tension of the water so bubbles travel further and faster, the skimmer will react very vigorously for a few days and then do nothing at all, eventually returning to normal when use of the additive or filter media ceases and a week or so has passed given the additive time to decay.

Benjammin · May 24, 2021

My tunze skimmer (different model) gets clogged at the air jet.

Benjammin · May 24, 2021

Little hole in the middle.

gentlefish · May 24, 2021

If it only chews out water, no bubbles your airline tubing may have slipped off at the pump head. Had this happen before when I tried to clean the line by squeezing water into it.

rvitko · May 24, 2021

They do clog with saltcreep at the air inlet, this generally becomes an issue at 4-6 months. You can preventatively inject a syringe of hot water down the air inlet every month to prolong the service life between disassembly. In cases where this happens very fast, the issue will usually be that it is submerged too deep or the silencer is in a location that it takes in moist salt laden air, such as under a canopy or in a back compartment.

___ · May 26, 2021

Thanks everyone. This is a brand new skimmer that just hadn't worked since day one. I don't have any additives in the tank, it just doesn't make bubbles. I've adjusted it up and down and done all the tricks, think I just got a .

rvitko · May 26, 2021

OK, when you say it does not make bubbles, does it not make foam or does it not make any bubbles at all? No bubbles at all I would generally think the impeller cover has detached from the pump, this is one of the more common problems on a new skimmer, probably 1/4 of the time in shipping this part comes off the pump and just needs to be reattached, it is what brings air to the pump.