<a href=showthread.php?s=&postid=15260154#post15260154 target=_blank>Originally posted</a> by Tschupe
Can anyone explain "wet skimming" as opposed to regular skimming ? THanks
Tschupe-
You would have better luck getting an answer from this Q&A thread if you added "ATB", "WM" or "BK" to your questions.
j/k
Seriously, my understanding of "Wet" and "Dry" skimming is as follows. Please correct me if necessary:
Wet skimming involves running your water level higher in your skimmer, thus obtaining a less concentrated "watery" skimmate. The foam head at the top of the neck appears wetter.
With dry skimming you run your water level lower, thus obtaining more concentrated (darker) skimmate. The foam head has a drier appearance, more like cappuccino foam with a lot of suspended crap.
Wet skimming is more aggressive, making sure that more organics and particulates get collected (along with more water). The collection cup fills up faster. One disadvantage to this method is that you have to watch your tank's salinity more carefully since more saltwater is removed when the collection cup is cleaned. I've seen one poster claim that they perform their water changes by extremely wet skimming, under the theory that the most organically laden water will be extracted through the skimmer.
Dry skimming fills up the cup slower, so it does not have to be emptied as often due to overfilling. I have read from one (long lost) source that dry skimming may allow more organics and particulates to build up on the inside of the neck and/or fall back into the reaction chamber. They claimed that dry skimming is claimed to be less effective at removing organics even though it is considered a benchmark of a good skimmer. Not sure if this is true or not.
Dry skimming may not be possible on tanks where the organic level is not high enough to allow a sustainable dry foam head. This is why nano tanks are most often unable to obtain dark, dry skim.
Lastly, please note that even a wetter skim will darken in a skimmer cup as it decomposes. If someone shows a picture of 7 days worth of skimmate, part of that dark color is due to rot. If someone shows you 2-3 days worth of dark skim, the color is a more accurate depiction of the skimmer's ability to skim dry. Also, collection cups that use darker colored acrylic tend to make the skimmate appear darker, and flash photography can also enhance the apparent color of skim. In other words, what you see is not always a good indicator.