Skimming....wet or dry?

[TheThingIs]

I can't seem to find any definate answers about this so I thought I'd throw this to you guys.

What is the difference between skimming wet and skimming dry in terms of the amount of docs pulled out?

Lee

[danny]

Good question, my guess would be that there would not be alot of difference. One would just be more diluted than the other.
Be interesting to hear what the panel says..

[Tony B]

Good question, my guess would be that there would not be alot of difference. One would just be more diluted than the other.
Be interesting to hear what the panel says..

Agree, I'm watching this one to see what the gods say...

[steve rochford]

and me :confused:

[Scott D]

well c'mon then panel - help us reefer out!

Cheers

[simon garratt]

basically none ime.

The act of running wet or dry is simply a reflection on the distance the skimmate travels from the water level within the skimmer body to point at which it breaks over the edge of the riser tube into the cup. The shorter the distance the wetter the skimmate becouse it hasnt had a chance to evaporate the exess water off the bubbles surfaces prior to them falling over the edge.

However....:)


The act of running a dry Skimmate does have a drawback in that the accumulated skum on the side walls of the riser tube does inhibit through friction the easy passage of foam past it, so it can lead to a decrease in performance overal.

Running wet aleviates this problem and allows better transport of waste into the cup area with less build up on the riser tube, howver it should be considerd that the wetter you run, the more salt your taking from the system within a given period of time and subsiquently trace elements.

How much is removed is anybodys guess as it would be difficult to test what with all the other crap in skimmate. but it should be considerd: ie if you run wet, then it may be worth testing perameters on a regular basis especially salinity if you seldom do water changes but have auto top up, rather than guessing that everything is Ok. A good skimmer can remove several pints in a week on some systems which can cause a gradual decrease in salinity and subsiquent lowering of trace element levels.


Regards

Si.:)

[Scott D]

Good info Simon

Cheers

[TheThingIs]

would another advantage of skimming wet be that waste is pulled out at an earlier stage of decay and therefore there would be less load on the nitrogen cycle and ultimately less nitrates?

Si, if you can recall giving me guidance on how to run my 850, which is now working great thanks. When I run the level at the point the cup twists in then my skimmate is extremely dark colored and gunky and I am pulling out about 1/3 liter per day. If I raise the level to just below the lip so I can just get the cup off without water dripping out (which is only about 1/4" higher) then I pull about 2 liters a day of paler skim. I'm trying to figure out which is best. WHen I do run wet then I do see my conductivity go down a point or 2 over a week but I'm happy to put in 2l a day of fresh salt water. Which way is better in terms of the overall quality of the water?

lee

[matt d]

would another advantage of skimming wet be that waste is pulled out at an earlier stage of decay and therefore there would be less load on the nitrogen cycle and ultimately less nitrates?

Si, if you can recall giving me guidance on how to run my 850, which is now working great thanks. When I run the level at the point the cup twists in then my skimmate is extremely dark colored and gunky and I am pulling out about 1/3 liter per day. If I raise the level to just below the lip so I can just get the cup off without water dripping out (which is only about 1/4" higher) then I pull about 2 liters a day of paler skim. I'm trying to figure out which is best. WHen I do run wet then I do see my conductivity go down a point or 2 over a week but I'm happy to put in 2l a day of fresh salt water. Which way is better in terms of the overall quality of the water?

lee

but arnt some skimmers designed to run on the drier side of skimming?
matt

[simon garratt]

Hi matt.

I dont think its so much a case of them being desighned to run wet or dry. i doubt very much that anybody would go to this extent of desighn reseaerch to be honest. most revolves around measuring a given amount of suspended waste and seeing how quickly it is removed from a test solution volume.

Its more down to the end user to decide how they want to run the skimmer. as it is, nearly all pro and intermediate skimmers have adjustability for this purpose. Wheras budget skimmers are simply plug and play and you get what you get.

regards

Si.G

[lenny]

i have always kept to skimming as wet as possble. as i have always wanted to get rid of the waste out of the solution,asap. i have just changed from an aqua medic m 1000 to a deltec apf600 and the new skimmer is skimming only removing a fractoin of what the aqua medic did. yes it is darker but then it,s only a tenth of that removed by the old one. i agree hat it,s darker because it takes longer to get into the cup and therefore evaporates the water off. i will probably goe back to the old one if i can not get the new one to skim wetter. lenny