Skimmer performance


Hi Tony ,
                Can you help , I bought a deltec 1456 at xmas just gone 2016 , three weeks ago the pump never restarted after a routine water change now 4 months old . The shop was helpful and replaced free of with a new ddc2 pump but annoying said they'd had every pump back and that's why the 1455 was brought out , this is disgusting from both the shop and deltec to have continuing selling them models knowing the chances are they will break down ! It doesn't end there , for the last three weeks I've tried to sort the skimmer but it seems way too powerful and after about 45secs on the lower setting just foams over continuous , all the messing about has caused the tank to stress and I've lost two fish and have £350 of foam maker . Can you advise I've tried highering the skimmer and turned Venturi to both extremes . Should we have been a different air intake perhaps.



Dear Tg

The information from the shop is not correct . The 1455 was released well before the 1456 by a couple of years hence why the model number predates the 1456.

Initially the DC pump of the 1456 had a sensor that detected when a foreign object entered the pump that was housed inside the stator, the chip could prove to be too sensitive in some instances and shut the pump down without good reason so Deltec had the chip moved to the controller to detect a change in current draw associated with a blocked impeller. I take it your shop replaced both the pump stator and controller with the newer version.?

Due to the design of the skimmer a pump cannot be too powerful as simply opening the water level adjuster will allow the water level to drop right down inside the skimmer even at full power, when you say turned the venturi what do you mean? The venturi sits on the suction side of the pump and cannot be turned.

Set the pump to level 4 and unscrew the water level adjuster until the water level and bubble break line drops down inside the neck to prevent copious amounts of foam entering the cup and allows the skimmer to collect ‘dry ‘ foam. The thread stick out between the adjustment knob and the water level assembly should be about 30mm as a ball park but will need fine adjustment to suit your tank.

If the skimmer produces copious amounts of foam this maybe associated with a water tension issue and the use of a food, additive, media etc you are using as if the surface tension of the water is effected and is too high a high density of foam will be produced. See video as an example.

Also make sure that the water level inside the sump is stable, if it fluctuates and rises up the water level inside the skimmer will also drop and increase meaning that when the sump level is low the skimmer may skim dry foam, when it runs high the skimmer may skim wet foam. You need to keep the level stable and set within the spec of the skimmer I.e Water level - min. 150 mm / max. 250 mm, around 220mm is ideal but keep the level set at that height.

Also check that the venturi is free of calcium carbonate build up and the airline is clear. Page 13 part no 7 for reference from the link below.

Can you please let me now where you purchased the skimmer and date of sale.

Also when you say you have lost two fish due to the skimmer I’m not sure how this would happen? You can run an aquarium without a skimmer succesfully if one chose too so there isn’t any mode of transport that a functioning or non functioning skimmer could kill fish so you may have something else going on there such as disease in the aquarium.

Best regards Tony