Hi we purchased a Nero 5 yesterday and set it up in the tank. Every now and then the pump gets quite loud and is not running silent. Is this a normal bedding in noise? Also can you give us an idea of what would be the best % settings for a mixed reef in a RS 250 tank set on random mode. thanks Justine
Thanks for your email, when the pumps are running in they can get into an oscillation where as if they are set on too long a pulse or set in constant mode the surface tension of the new plastics can allow air to collect inside the back of the stator near the back bearing and cause the pump impeller to get into a slight wobble .Equally if there is any of the food grade silicone grease the pumps are shipped with blocking the four front impeller holes air wont be able to exit from the front of the impeller.
To help overcome possible break in issues we suggest removing the grease as per the video below and setting the pumps into pulse mode for 3-5 days at around 80-100% 3 seconds on and 3 seconds off, this variable pulse will keep air flushed out of the impeller while breaking in and the pump will start to slime up inside and the plastics surface tension will drop and bubbles will stop collecting at the back of the pump. After this time you can default to the flow pattern that your choice.
I would also set the pumps in pulse for a few days after any complete cleaning as again the clean plastics will start to attract air for a few days after.
Best regards Tony