Functioning
The skimmer needed some days of running-in. The foam completely fills the body, as we expected – seen the pump. The foam is really compact and the bubbles very small. Visually speaking foaming and coloration seem very good.
The suggested level in sump is, as always, about 20 cm. In this way the suction of the air and the pressure of the water are perfectly balanced. Obviously (we want to repeat this for the ones who don’t know) they’re in equilibrium because the skimmer has been built in this way, that’s the reason. So I suggest to be very close to 18-19 cm as the skimmer askes, in our thest the slider was at exactly 20 cm. The foaming also strongly depends on the salinity: the more salinity we have, the better the skimmer will work. We have always kept salinity at 35 per thousand.
After six months of use we can affirm that the skimmer ATB medium size 25 has worked perfectly. Perfect values in aquarium, few maintenance and always efficient.
The ATB and its maintenance
Thanks to the brushes inside and to the drain at the bottom the maintenance is reduced to a minimum. Sure, we would have liked to have the same countersink as for the Red Sea RSK 600 (review) that would have allowed us to keep in control the level of foaming but, beyond that, the skimmer worked perfectly. We placed it in sump on February and we kept on going until few days ago.
Performances and measurements
The builder declares for this skimmer an amount of water of 2.800/2.500 l/h and 1.500 l/h of air, depending on the pump you use. These numbers are influenced by a lot of different variables, for example the height of water in sump, the height of the water column inside the cylinder and most of all the salinity, that we kept 35 per thousand. The air/water relationship then it’s 0,6.
Unluckily, given the particular conformation of the skimmer with the drain at the bottom we couldn’t measure the treated wayer. While for the air we used our classic flowmeter Sander that measures the air from a minimum of 100 l/h to a maximum of 1200 l/h. These values then have to be increased by 10% in order to consider the lacks of the device.
So, we obtained an amount of treated air about: 1320 l/h (1200 collected+ 10%), with air totally open. The value was pretty stable. We practically obtained the maximum measurable with our flowmeter. Chapeau. Another thing we noticed is that our value never changed both with clean and dirty skimmer. And it’s also pretty close to what decleared by the builder, with a gap of 12%. A really good result, our personal record here on DaniReef.
The skimmer is very quiet, the whole aquarium a bit less. We did three measurements, all one meter away from the aquarium and the sump. We obtained the following results:
Sound pressure at 1 meter with all the utilities on and closed doors: 44,6 dB
Sound pressure at 1 meter with the skimmer switched off and open doors: 46,6 dB
Sound pressure at 1 meters after switching on the skimmer: 47,7 dB
The difference in the sound pressure measured with the skimmer on and off is 1,1 dB, very moderate, I would say, so the skimmer should have a noise about 47 dB.
The sound level meter is the usual VOLTCRAFT 320, digital meter IEC 651 Type II that is enough reliable. Given the nature of the noise all the measurements have been done with the attenuation curve dBA.
The article continues on page three with the maintenance costs and our conclusions.
