too much skimmer?

[gtbarsi]

There is such a thing as too much skimmer!

If the neck of the skimmer is too big for the system the skimmer will not be able to fractionate enough DOCs from the water to form a stable foam head. This will result in a lack of skimmate in the collection cup, preventing the export of the DOCs and leading to their eventual breakdown to ammonia, nitrite, nitrate, or phosphate to name a few.

A properly sized skimmer once broken in and adjusted should have two noticeable states. Active where the foam head is going up the neck and depositing skimmate in to the collection cup, and in-active where the foam head is breaking down low in the neck of the skimmer.

If a skimmer is always in the active state one of two things is going on.
1. The skimmer is not adjusted correctly, this is evident if the skimmate is very thin, and lacks a dark color. Often skimmers not adjusted properly this way flood their collection cup frequently.
2. If the skimmate is not very thin and is dark in color then chances are it is undersized for the amount of DOCs in the system. Upgrading is recommended since the excess DOCs the skimmer is failing to remove are breaking down in the water, causing additional nutrients that could have been exported by the skimmer.

Jwilson,

The fact that you are seeing a large volume of thick dark skimmate suggests that the skimmer does not seem to be oversized. If you see a sudden drop off of skimmate production then you may want to put the skimmer on a timer or downgrade. Unless that happens just go with it!

 

[hummer]

My skimmer c99 on a 120 mt and 180 sump

 

[jwilson]

Jwilson,

The fact that you are seeing a large volume of thick dark skimmate suggests that the skimmer does not seem to be oversized. If you see a sudden drop off of skimmate production then you may want to put the skimmer on a timer or downgrade. Unless that happens just go with it!

what is's producing now isn't as dark as it was initially, but it still seems to be pulling funk out of the water. this is after 6 days.

 

[gtbarsi]

That looks pretty thin. I'd adjust the skimmer to be a ltitle more open on the drain. That will produce a thicker skimate.

 

[H@rry]

That brings up a question I often wonder about:

I know a darker skimmate means that it has a higher concentration of "nasties". BUT, if a wetter skimmate is removing some "nasties" that a drier skimmate left behind, is it not a little more efficient? I understand the issue of removing more water and the need to maybe add a little salt mix to the top off water.

My question is: after a week with these two scenerios:

a. Skimmate that looks like leftover coffee that has boiled in the pot too long
b. Skimmate that looks like chicken broth

Which one would have removed the most "nasties"?

BTW, sorry 'bout the thread hijack (well, not really)

 

[gtbarsi]

That brings up a question I often wonder about:

I know a darker skimmate means that it has a higher concentration of "nasties". BUT, if a wetter skimmate is removing some "nasties" that a drier skimmate left behind, is it not a little more efficient? I understand the issue of removing more water and the need to maybe add a little salt mix to the top off water.

My question is: after a week with these two scenerios:

a. Skimmate that looks like leftover coffee that has boiled in the pot too long
b. Skimmate that looks like chicken broth

Which one would have removed the most "nasties"?

BTW, sorry 'bout the thread hijack (well, not really)

There is a lot to this but generally you want to achieve a balance between the two. Here is a good article What is Skimming? by Randy Holmes-Farley - Reefkeeping.com, the section What Collects at Air/Water Interfaces, and Why? is where it begins to get in to what is in skimmate why you want that balance between wet and dry.