Over sized skimmer?

[cment]

Well the topic was brought up in a FS thread so I thought it would be appropriate to start some discussion on the subject since it applies to a new skimmer I just added to my system. I have a heavily stocked 25g cube with about a 10g sump which probably holds about 6g. I had an SCA 301 on my tank and it had great skim-mate, nice and dark which i would empty about every 5 days or so. Since I do feed heavy and will continue to do so I thought maybe I should add a larger skimmer to pull more organics from the tank. I found a great deal on a RO NWB110 and added it. Since adding this new skimmer, it has not performed as I thought it would. I no longer get nice dark skim mate as before but yet more watery light green skim mate. Is my skimmer too large for my system? Maybe the skimmer is still in a break in period. I have only had it up and runner for about 2 weeks with nothing else changing. I do have this same skimmer on a frag tank which is around 45g of total water volume and get nice, dark skimmatee. Should I go back to the SCA 301?

 

[lsu_fishfan]

You could try tuning it to get darker heavier skim

 

[cment]

LSU_fishFan;984767 wrote: You could try tuning it to get darker heavier skim

Seems like I have been constantly trying to find its "sweet spot" but have been unsuccessful. Either I get too much water in the collection cup or no skimmate at all and this is with less than a 1/2 turn of the gate valve in either direction

 

[tonymission]

Bassett22;984802 wrote: Here is my understanding, and I'm far from a smart reefer, so I really look forward to some one correcting me, but a skimmer that is too large, will process water very quickly and strip the water of all docs (dissolved organic compounds) that are required for the foam to build and rise in the neck.

Most people think so what? Strip the water! That's what we are trying to do.

But the massive skimmer will strip the water only if the water has enough DOCs to create foam, so the tank will sit and build up waste until it gets high enough to form a head. Then it will strip it. So your DOCs will be in constant fluctuation.

Can anyone refute or correct this line of thought?

It's agreed that most skimmers are overrated, and getting the next size up or two is usually reccomended. But obvioulsly using a skimmer the size of the ga aquariums won't work on a 14 gallon nano cube right?

If that's not right then it sure sounds pretty good!

I know when I was running a massive RO external on my 90g it was exactly as you described. Either foaming every now and then or way low in the skimmer body. I couldn't ever get it dialed in and the overflowing can do a number on your salinity with the top off kicking in to compensate.

 

[jead85]

I agree with that theory. at one point I had a Super Reef Octopus XP2000 connected to my frag tank with a few fish in it. I had a very hard time keeping it dialed in. Undersized isn't good, oversized definitely sucks too..

 

[northgahillbilly]

Ive got an oversized skimmer, but not to that extent. Ive found I have to run it lower than "normal" and the skimmate collects in the neck as opposed to spilling out into the cup, but it pulls about a tablespoon of solid gunk a week

 

[berje]

Maybe he doesn't have enough flow going through his sump?

Maybe more flow through sump will help?

 

[jmaneyapanda]

1) Id caution against "creating a problem" rather than "having a problem". Dark skimmate isnt a indicator of a healthy reeef. Are your water levels OK? Are you animals OK? If you dont have a problem, dont try to find one.

2) that theory about skimming is a little off. Foam fractionation is a pretty simple biochemical process. Adding more bubbles and more contact time cannot impair the fractionation process. The bubble boundary layer between air and foam is where this will collect. Whether that boundary layer is in the cup, is dargk brown, or in the neck, or wherever, it ISNT in your tank water and therefore the skimmer is doing what it's supposed to.

 

[cment]

jmaneyapanda;984936 wrote: 1) Id caution against "creating a problem" rather than "having a problem". Dark skimmate isnt a indicator of a healthy reeef. Are your water levels OK? Are you animals OK? If you dont have a problem, dont try to find one.
I understand where you coming from and yes my tank and its inhabitants are doing great. All levels are acceptable. (standard parameters)

2) that theory about skimming is a little off. Foam fractionation is a pretty simple biochemical process. Adding more bubbles and more contact time cannot impair the fractionation process. The bubble boundary layer between air and foam is where this will collect. Whether that boundary layer is in the cup, is dargk brown, or in the neck, or wherever, it ISNT in your tank water and therefore the skimmer is doing what it's supposed to.

As I do agree with the fact that if it isnt in the water then the skimmer cannot pull it out, I have however increased feeding a little without changing anything else (eg. water changes, bio load) and seen what looks like a reduction in skimmate as compared to my previous skimmer. I am not necessarily alarmed by this but it just struck me as odd.