do you use a filter sock?
- Thread starter Reefski's
- Start date
I run a filter sock and typically change it every 2-3 days (every day if I am dosing any vodka). My measurements by Hach colorimeter are:
ammonia <.02ppm (undetectible, .02 is lower limit of detection)
nitrate <.05ppm (undetectible, .05 is lld)
phosphate .02ppm
For comparison, these values for NSW near reefs are about (approximate as values vary on different reefs):
ammonia ~.02ppm
nitrate ~.06ppm
phosphate ~.003 to .03ppm
For those who don't believe they're nitrate factories, I've got a way to prove it. Clean out your skimmer's collection cup and run it for 24 hours with a filter sock and mark the level of skimmate collected. Then clean out the collection cup again and run it for 24 hours without a filter sock. You'll be amazed at the difference--there's about 5 times as much skimmate when running a filter sock.
I used to run my tank without a filter sock for about 2 years. If anything I saw a slight decrease in skimmate when I went to a sock.
I know many people think the more skimmate the better, but in this case the larger amount is due to there being more ammonia available. Who knows how much of it manages to get past the skimmer?
This makes no sense. Skimmers cannot remove ammonia, nitrate or phosphate. They can only remove larger molecules. They "remove" these nutrients ONLY by removing the molecules that contain N or P atoms before they are broken down to release these atoms as ammonia, nitrate or phosphate. If these substances were being produced in the filter sock because of breakdown occurring in the sock then there should be LESS to skim out not more.
Also, filter socks remove plankton from the water column, so they're impacting your food chain.
Absolutely true. No one has really proven how much plankton really exists in aquaria nor how important it is to coral growth. Many SPS corals consume mostly bacterioplankton and very small particles. Many of these are not removed that easily by filter socks. Skimmers are more efficient at removing them. Even accepting that they may remove a significant amount of plankton, IMO when they are cleaned regularly, their benefits outweigh their only downside of plankton removal.
Allen
finneganswake
In Memoriam
Actually, there have been plenty of recent books (Borneman and Calfo, for example) that say that most reefers are seriously mistaken about the feeding habits of sps corals. They say that they don't get nutrition from phytoplankton (I'm assuming this is what you're referring to when you say small particles) but they do get a fair amount of nutrition from smaller zooplankton. They say they think the reason people believe that sps don't feed on zooplankton is because their polyps aren't as large as lps corals, so therefor they can't eat the same stuff and must feed on the smaller phytoplankton. However, sps from the ocean typically test at 10% nutrition from small zooplankton. This is in nature--with our inferior lighting in tanks, who knows how much they need in a captive environment? This is exactly the type of plankton that a filter sock removes from the water column.
finneganswake
In Memoriam
Actually, there have been plenty of recent books (Borneman and Calfo, for example) that say that most reefers are seriously mistaken about the feeding habits of sps corals. They say that they don't get nutrition from phytoplankton (I'm assuming this is what you're referring to when you say small particles) but they do get a fair amount of nutrition from smaller zooplankton. They say they think the reason people believe that sps don't feed on zooplankton is because their polyps aren't as large as lps corals, so therefor they can't eat the same stuff and must feed on the smaller phytoplankton. However, sps from the ocean typically test at 10% nutrition from small zooplankton. This is in nature--with our inferior lighting in tanks, who knows how much they need in a captive environment? This is exactly the type of plankton that a filter sock removes from the water column.
finneganswake
In Memoriam
Huh? How did that double post???
Reefski's
Active member
so you do not use a filtersock? but do have a DSB.
my 260 g tank is BB.
over the weekend i have just set up a 55 gallon tank withy 6" sand that is connected to my main system and draws from the sump.
right now i have my sump with a filter sock and the skimmer draws water before the filter sock and the new refusium, DSB draws water from just after the filter sock. how does that sound?
Carl
my 260 g tank is BB.
over the weekend i have just set up a 55 gallon tank withy 6" sand that is connected to my main system and draws from the sump.
right now i have my sump with a filter sock and the skimmer draws water before the filter sock and the new refusium, DSB draws water from just after the filter sock. how does that sound?
Carl
rutz81
New member
Finnegan: Considering that so many people are running filter socks and have "successful" tanks, there's got to be something else behind the whole filter sock dilemma. IMO, SPS DO feed to an extent. But, I also feel that the typical 100 Micron filter sock do remove even close to all the zoo/phyto plankton in the water column. I'm sure there are much more plankton in the water that is smaller than 100 microns, and therefore would go right through. I am not trying to argue with you, but, there are so many SPS tanks that run socks, and still get great growth and color.
Dave
Dave
finneganswake
In Memoriam
Obviously the phyto will still get through, as it's mostly in the (I think) 2-10 micron range. I doubt that any zooplankton, except maybe the very smallest, could get through.
And I agree with you that there are plenty of nice tanks with socks. I just think that removing the sock is one of those little things that helps.
lossman
New member
In some cases it may help. I'd like to be able to remove our socks, but the amount of microbubbles generated by our overflows is just too much. I think the micro bubbles are probably worse for the inhabitants than the use of the socks. And before you suggest it, I have already tried a large number of modifications and none work as well as the socks. I even had a tank maintenance person come over and attempt to get rid of most of the micro bubble problem with no luck. I'll stick with the use of my socks. 
dnjan
Premium Member
I don't believe there is a direct relation between your theory and your experiment. The increased skimmate production (with a filter sock) is probably due to the intereference with bubble stability for your skimmer caused by the larger particulate matter when you do not have a filter sock in the system. With the filter sock removing the larger suspended particles, you skimmer probably runs more efficiently.
finneganswake
In Memoriam
I don't think this is true, as the skimmate with the filter sock off is downright nasty, while the skimmate produced with the filter sock on looks like really weak tea. Also, there's so much distance between my overflow's pipe and my skimmer intake that I don't think many large particles manage to make their way over to it.
dnjan
Premium Member
Actually, what you said kind of confirms what I thought - the suspended detritus particles (without the filter sock), would reduce the bubble stability, resulting in less liquid being skimmed. But the liquid that was skimmed would include at least some of the suspended detritus (stink). With the sock in place (and many of the suspended particles removed), your bubbles are more stable, and your skimmate is therefore wetter. (Unless you are changing the adjustments of the skimmer for your with or without sock conditions.)
As far as the detritus particles not making it across youyr sump - I should probably clarify that I am talking about detritus particles in the hundred to a few hundred micron size. These particles would take a while to settle in still water, and I assume that you have some movement in your sump.
As far as the detritus particles not making it across youyr sump - I should probably clarify that I am talking about detritus particles in the hundred to a few hundred micron size. These particles would take a while to settle in still water, and I assume that you have some movement in your sump.
dnjan
Premium Member
Particle Size removed by Filter Socks
Particle Size removed by Filter Socks
Preservation of the various planktons may be another reason to clean your filter sock fairly often. Any time you have particles being retained against a porous filter, you get an accumulation of particles on the upstream side of the filter. As these particles accumulate, two things happen:
First, they gradually reduce the flow rate through the filter, eventually resulting in clogging.
And Second (and most important for preservation of plankton), this accumulation of material effectively decreases the apparent opening size of the filter.
This decrease in the effective opening size can be fairly significant - an order of magnitude or more.
Translation - A 200-micron filter sock that has been allowed to accumulate a considerable layer of particles can easily be removing materials as small as 20-microns or smaller.
Particle Size removed by Filter Socks
Preservation of the various planktons may be another reason to clean your filter sock fairly often. Any time you have particles being retained against a porous filter, you get an accumulation of particles on the upstream side of the filter. As these particles accumulate, two things happen:
First, they gradually reduce the flow rate through the filter, eventually resulting in clogging.
And Second (and most important for preservation of plankton), this accumulation of material effectively decreases the apparent opening size of the filter.
This decrease in the effective opening size can be fairly significant - an order of magnitude or more.
Translation - A 200-micron filter sock that has been allowed to accumulate a considerable layer of particles can easily be removing materials as small as 20-microns or smaller.
finneganswake
In Memoriam
That's a possibility, I suppose, but given that my nitrates and phosphates are both undetectable, it seems unlikely that my skimmer isn't working at full capacity.
Also, if you read the manuals of most high-end skimmers, they say that dirty skimmate is far preferable to wet skimmate, so, again, it sounds like my skimmer is doing what it's supposed to.
My theory is that all of the wet skimmate that is produced when I put a filter sock on is just fouling agents released from the rotting stuff in the filter sock. I don't know--maybe it's because I only run a filter sock when I have blown off my rocks; it's possible that all of the skimmate is due to the large amount of detritus shed from the rocks during this procedure.
This has made me think, though--I'm going to post on Anthony Calfo's forum about this and see what he thinks; he's (IMO) the god of skimmer knowledge. I'll let you know what he says
finneganswake
In Memoriam
Re: Particle Size removed by Filter Socks
Re: Particle Size removed by Filter Socks
But how many copepods will make it through the cleanest 200 micron filter? I don't think that any but the smallest zooplankton can make it through something like this--remember, 200 microns is EXTREMELY tiny.
Re: Particle Size removed by Filter Socks
But how many copepods will make it through the cleanest 200 micron filter? I don't think that any but the smallest zooplankton can make it through something like this--remember, 200 microns is EXTREMELY tiny.
lossman
New member
When I ran my tank without the socks for 24 hours to see what the skimmer would do, not only did I not notice any difference in the amount of skimmate, but the quality seemed to be the same also. I did not make any adjustments to the skimmer between with or without the sock. Perhaps if I ran it longer than 24 hours I would have seen a difference.
Sindjin
New member
With my setup, I have 2 OverFlows going into my sump. One goes directly into the skimmer but the other I just have going to the sump. I'm adding a Sock to the second one because I am seeing a lot of build up in my sump. I think it is getting blown back into the aquarium. In addition, I am noticing a periodic haze to my water ... Im thinking it could be caused by the extra detritus getting spit back into the aquarium from the sump.
Hopefully a Sock will correct this. We'll see.
Hopefully a Sock will correct this. We'll see.
