Performances and Measurements
Air Inflow
The manufacturer doesn’t specify the water capacity of this skimmer, but we can deduct it should around 800 l/h, this is unfortunately not measurable because the outflow is submerged. On the other hand, the air drawn in is stated to be between 1000 and 1300 l/h.
For measuring air capacity we used our classic Sander flowmeter, which measures air flow from a minimum of 100 l/h to a maximum of 1000 l/h, the values have to be increased of 10% to adjust for leaking caused by the fluxmeter itself.
We obtained an air flow of 1045 l/h (950 measured + 10%) with the air inflow at its maximum as there are no faucets to adjust it.
The value is relatively stable even though it showed a small fluctuation between 900 and the minimum (which still needs to be increased by 10%). This is probably due to the hydraulic phenomenon know as the water hammer, which originates inside the pump.
The air inflow has been reduced starting from the 1150 l/h obtained by calculating the mean of the minimum and maximum values stated, to the 1045 l/h measured. It is only a 9% difference, practically negligible , as it still has a very impressing measured value!
I had never encountered skimmers with such air flow values. Unfortunately I didn’t get to open the pump to examine the impeller, but I am sure that the pump has been notably engineered. I have seen three other skimmers working with the same pump (Elos PS2000, LGMAquari LGS850 e Ultra Reef Akula UKS 180) and they didn’t even get close to these values, in fact they had a 50% less air inflow.
The air inflow measurements were taken with a sump water level of 21 and 23 cm, without any significant difference showed at different heights, as we actually expected. Salinity was at 35‰. We should remember that skimmers are extremely susceptible to changes in water density, different values resulting in very different skimming performances.
Noise
The skimmer is incredibly silent, we took three measurements, all at 1 m distance from the tank (and sump) and we obtained the following results:
Acoustic pressure at 1 meter with all aquarium devices on and support doors closed: 48 dB.
Acoustic pressure at 1 meter with only return pump on and open doors: 56.4 dB.
Acoustic pressure at 1 meter with return pump and skimmer on: 57.1 dB.
The difference in the measures of acoustic pressure with the skimmer on and off is only 0.7 dB, a negligible value.
We can therefore state that the Vertex 180i is an exceptionally quiet skimmer that can be placed in the sump without worrying.
The phonometer used for measuring acoustic pressure is the usual VOLTCRAFT 320, digital phonometer IEC 651, Type II, very accurate. Considering the type of noise we needed to measure, all the measures were recorded with dBA wave attenuation.
