Skimming in a Barebottom tank. - Page 5

redwinger · 02-15-2006, 11:40 AM

That makes more sense sean.

Don't get me wrong the deltecs are awesome skimmers just alot of money when there are others that will do just as good a job for allmost 1/3rd the price.

Geoff turn off your recirc pumps on a recirc skimmer and nothing will be skimmed out.

Wiskey · 02-15-2006, 12:28 PM

Ya the recerc pump is the one that has the venturi and needle wheel in it, without it you don't get any air.

Whiskey

NoSchwag · 02-15-2006, 12:41 PM

geoff what about removing the things before they have a chance to dissolve?

Right now my dwell time is probably less than 5 seconds. I think I'm doing it right because my nitrates are .02, my tank is crystal clear, I don't use anything but a skimmer to remove particles, and I dont have to clean my glass that often. Not to mention I am a hibitual overfeeder.

Everything I have ever read about skimmers talks about dwell time. I am honestly starting to think that dwell time is overrated. There is no way my skimmer has more that 5 seconds dwell time but everything seems to be going right..

I'll take a video of what I'm talking about if someone hosts it.

elephen · 02-15-2006, 12:47 PM

NoSchwag - when you take it let me know, I have a couple of servers and I would be more then happy to put it up for you.

Wiskey · 02-15-2006, 01:12 PM

I would love to see a video of a working bekett, elephen's may be just that, but I can't see that video until I get home.

Whiskey

Geoff · 02-15-2006, 01:15 PM

Quote:

Originally Posted by NoSchwag

geoff what about removing the things before they have a chance to dissolve?

Right now my dwell time is probably less than 5 seconds. I think I'm doing it right because my nitrates are .02, my tank is crystal clear, I don't use anything but a skimmer to remove particles, and I dont have to clean my glass that often. Not to mention I am a hibitual overfeeder.

Everything I have ever read about skimmers talks about dwell time. I am honestly starting to think that dwell time is overrated. There is no way my skimmer has more that 5 seconds dwell time but everything seems to be going right..

I'll take a video of what I'm talking about if someone hosts it.

this may very well be true. i could very well be thinking to old school on this. it maybe that it is the larger particles that are causing the problems and not the DOC's. if this is truely the case than sheer bubble volume is more important than dwell time and getting the bubbles as tiny as possible.

it may very well be the larger particles are the ones we need to be removing. since wet skimming is more efficient that dry skimming. dry skimming will pull out the smaller DOC's if the dwell time is sufficient. wet skimming will lift the larger particles out of the skimmer.

anybody know for sure?

sorry, i am one who would rather understand why than to just go with what everyone says is good.

G~

NoSchwag · 02-15-2006, 01:15 PM

Okay I'll be taking it when I get home.

I'm looking foward to it

Hopefully it helps people in tuning their skimmer.

Also if i'm doing it wrong, hopefully someone will call me on it.

Wiskey · 02-15-2006, 01:39 PM

Quote:

Originally Posted by NoSchwag

Okay I'll be taking it when I get home.

I'm looking foward to it

Hopefully it helps people in tuning their skimmer.

Also if i'm doing it wrong, hopefully someone will call me on it.

Great, can't wait

One question, do you need to take off all those bolts on the top of the skimmer cup to take the lid off?

Thanks,
Whiskey

elephen · 02-15-2006, 01:53 PM

I'll video my skimmer in action tonight after I clean it up a tad, it gets so dirty in 2-4 days that you can't see in.

NoSchwag · 02-15-2006, 02:03 PM

Yeah Wiskey but it only take's seconds.

Geoff · 02-15-2006, 02:55 PM

Quote:

Originally Posted by NoSchwag

geoff what about removing the things before they have a chance to dissolve?.

i think most of the stuff we are trying to remove is already dissolved. all of the waste products from out corals are already dissolved into our water column.

ok, back to the recirc skimmers. how many pumps are on these? so the supply pump is non-air injecting? only the recircs are? why not all of the pumps air injecting?

G~

Wiskey · 02-15-2006, 03:05 PM

Quote:

Originally Posted by Geoff

i think most of the stuff we are trying to remove is already dissolved. all of the waste products from out corals are already dissolved into our water column.

ok, back to the recirc skimmers. how many pumps are on these? so the supply pump is non-air injecting? only the recircs are? why not all of the pumps air injecting?

G~

That is correct, only the recerc pump is air injecting, I think the supply pump is non air injecting because it is supposed to run at a very low flow rate for max dwell time, I could be wrong though.

Whiskey

elephen · 02-15-2006, 04:54 PM

Quote:

Originally Posted by Geoff

i think most of the stuff we are trying to remove is already dissolved. all of the waste products from out corals are already dissolved into our water column.

ok, back to the recirc skimmers. how many pumps are on these? so the supply pump is non-air injecting? only the recircs are? why not all of the pumps air injecting?

G~

G- Any and all decent recirc nw skimmers I have seen have a minimum of 2 recirc pumps on the skimmer plus a feed pump to put water in there.

Here is a shot of a nice recirc NW that sits in my closet

This was when I first setup the skimmer and was adjusting some stuff. Here are some more pics of it: http://reefs.elephen.com/pics/categories.php?cat_id=6

Geoff · 02-15-2006, 05:03 PM

Quote:

Originally Posted by elephen

G- Any and all decent recirc nw skimmers I have seen have a minimum of 2 recirc pumps on the skimmer plus a feed pump to put water in there.

Here is a shot of a nice recirc NW that sits in my closet

This was when I first setup the skimmer and was adjusting some stuff. Here are some more pics of it: http://reefs.elephen.com/pics/categories.php?cat_id=6

why is the feed pump not air injecting? what kind of pump is the feed pump? is it something real like a velocity T1? something that will not be affected by any kind of pressure change in the water in which it is located. having made a bazillion skimmers, i am just not seeing where this is an advantage, unless what i was asking about the larger particle size is what is really needing removing. if this were the case than i would think a needlewheel would not be the best method. it could shake loose the particles as it passes through the needlewheel.

G~

three90s&125sump · 02-15-2006, 05:17 PM

I think the entire point of having the recirc pump is to have slow flow (feed pump 400 GPH) with a small skimmer( 24 inches tall X 12 Inch Daiameter) and a huge dwell time (3 recirc needle wheel pumps 700GPH X 3). With a set up like that I think it would be quite possible to have the effieciency of the skimmer be equal to that of a skimmer that is 10 feet tall with a diameter of 12 inches flowing 2100GPH through it.

If there were some way to compartmentalize the chamber into 3 or 4 seperate chambers with it own dedicated recirc pump and a graduated method of feeding each one as to be sure that all the water entering the next chamber would have have at least 80% dwell time in the previous chamber, I could see the water coming out of the final chamber 99% devoid of all DOCs and particulates.

I think they are very efficient at skimming but I think the feed rate of the skimmer is its limiting factor. For example : My return pump is pumping 2600 GPH through it. That means with each pass through the skimmer the above mentioned hypothetical skimmer would only process 15% of the water entering the sump. That means it is missing 85 percent of the DOCs with each tank cycle now a skimmer that is processing 2600 GPH but is only 50 percent efficient at removing DOCs would still be removing 35 percent more than the recirc skimmer. I have to cut this short, I'll be back later if anyone want to comment now.