Yes and what exactly does that have to do with over skimming? We're talking about two different things.

Thanks Denny that's a long read but very good

You said that skimming removes about as much bacteria as a water change, which really isn't the case. It sounded like you didn't understand how skimming worked.

:pop2:

A skimmer can only remove bacteria from the water column, same as just removing the water. Bacteria adheres to surfaces significantly more than the water itself thus removing the water or skimming heavier will not diminish a bacteria population period. This applies to carbon dosing or zeo, over skimming has no negative effects on a bacteria population, even if you're dosing it provided you dose downstream. So my point was when over sizing a skimmer to your bio-load the risk relates to removing excess essential elements such as potassium not bacteria. Make sense yet?

I understood your central point from the start, however saying a skimmer removes as much bacteria as a water change was mixed in there. Fact is, you can't compare the two. And truthfully a skimmer can remove a lot of bacteria.

Ok, but if you had one, it can help you determine whether your bioload is too high. :)

Ok, I'll give you that :)

However, that doesn't really address the question.

Skimmer x is good for 200g @ light load, 150g @ med load, 100g high load. How does one determine if skimmer x is appropriate for their 120g tank?

Personally, I've been doing this a couple years now, I just know. I know my bio load, pretty comfortable guessing bio load capacity, and I'm confident in my abilities to size a skimmer.
But for most consumers new to the hobby, what does that mean? Does skimmer x meet my needs? Or do I need x +/-1 for my tank? Generally bigger is better, but if I go too large, I may not have enough load to get proper foam development.

All theoretical discussion with no real answer, just something to kick around.

Absolutely, found this out buy only running skimmer part time. My skimmer is rate more than double my tank volume and while running 24/7 I only ever got murky water and found it hard to tune the skimmer. Now running at night my skimmate has become very dry and sludgy.
This may put me at a light bioload for skimmer but fully stocked for tank size

Disagree, if for some reason I wanted to remove bacteria from the water column I could change 100% of the water which would be far more effective than what a skimmer could do. Ultimately changing a given amount of water on a certain frequency would compare directly to what a skimmer would accomplish, same as removing any organics. But that's all pointless information irrelevant to anything we're talking about here, the comparison was only made based on the common misconception large water changes are harmful because they remove beneficial bacteria, so I was making the same comment relating to large skimmers...

Again that's a poor example. Bacteria multiply exponentially, it's not like removing a dissolved organic. Doing a 100% water change would remove all of the bacteria in the water (once), a skimmer will remove continuously.

I agree, a bit off topic. Sorry for that

Here's my take on that. I don't care at all about any bacteria in water, so if it's there or not, makes no difference. The amount free in the water column is insignificant, so let the skimmer take out however much it wants.

+1

If you're doing zeovit or dosing carbon, there will be a significant amount of bacteria in the water column at times. Enough that you can see clumps

Going back to your original post, I suggest that you get a skimmer that is rated for your water volume as 'heavily stocked' and leave it at that.

Charles

Nope, sorry, no clumps. And if there were clumps, that's bound and probably not really active in what I want bacteria to be doing, and therefore, again, insignificant. The only bacteria I'm concerned with are those on substrate, which are not removed in any amount, by any means, that concerns me.

Yes, I think that's the real answer, just thought it would be an interesting discussion

It has been and is. I just suffer from the guy tendency to offer solutions instead of discussing things :)

Charles

When dosing carbon (and zeo is carbon dosing as well), a biofilm of bacteria is formed. It can form on the sand, rock, zeolites, carbon/gfo, biopellets, glass - whatever. This occurs because dosing organic carbon removes a limiting factor in growth, allowing nitrogen processing bacteria to thrive. These ARE the bacteria you're concerned with. The 'clumps' or biomass bacteria occur when the biofilm becomes too thick, and excess bacteria break off (also happens when shaking zeolites and releasing 'mulm'). But this is just a visual example of what already occurs when dosing carbon; the bacterial count in the water column goes up. You actually WANT to skim/remove these because in doing so you also remove nitrogen and phosphorus from the system. So while it's true that generally you shouldn't be concerned about removing 'too much' bacteria from the water column by protein skimming, that doesn't mean it doesn't happen. It happens to a degree in every reef aquarium, and moreso in those that dose organic carbon.

BTW I do feel this is relevant to the conversation, as dosing carbon (and the resulting increase in bacteria) should actually be considered as an increase in the bioload of an aquarium IMO. That is, if you are dosing carbon, you should increase the capacity of your skimmer accordingly.

Like you said, excess bacteria. The ones I don't care about. Maybe I'm just not understanding your point, but I will agree that aggressive skimming is desirable to remove this excess.

I have only seen clamping in my plumbing. But since dosing biomate it has gone. I do know of carbon dosing peeps who said the rock or sand looked dirty from the mulm build up though. But with proper husbandry it shouldn't get to that point

IMO the solution lies in DC controllable pumps. Get a skimmer that is easily oversized, and turn it down until you get a consistent foam head. Problem solved?

Really? The last thing I would ever use is a controllable pump on a skimmer. Over complicates things, adds additional cost that doesn't need to be there, and once set, you probably never have to adjust again.
An appropriately matched skimmer/pump set should already be at the right values and the only tweaking should be air volume and water height.

I know I'm old and set in my ways, but adding features for the sake of adding features is not something I buy into.

Sure Says the guy who's never owned a dc skimmer lol

fwiw dc skimmers are actually cheap for what they are rated to , more so than a lot of the more common AC brand names.


Remember the article on skimmers and how much they actually removed , (less than %20 if i remember correctly ) I believe the reef octopus performed one of the worst yet still a go to skimmer for a lot reefers.So I'm not sure on how good a job our current technology actually is.

Back to the bac.....


While there are bacteria that can and can't be skimmed (see article) the ones that we want are indeed skimmed out ......those rock and surface clinging bacteria everyone speaks of.

But how are they skimmed if they only attach to rock?

My only beef with dc skimmers and dc pumps all together is the crappy lifeline and cheap parts they can have.

Fair enough, but I don't conceptualize the point. Seems odd to want a controllable pump that I don't want to change. Just start with the right sized pump and go.

But, I've been known to be wrong before. Not often, but it happens :razz:

I just have no interest in fiddling with things, I want to plug it in and be done with it.

I do like the idea of the controllable pumps , as I found it very handy to fine tune a good head as well the slow start is a nice feature, but there are also things I don't like either ,so I didn't go dc for my new skimmer either I went the other way.

I def agree get something adequate from the start regardless of the name or style.

One feature that is a must have for me on most any skimmer is a large cup , I hate small cups:)

I'm gonna get flamed for this but oh well, lol in my tank (100 gallons ish) i have naso tangs,blue tang, yellow tang, kole tang, 2 clownfish, 8 green chromis, male& female manderin goby, 3 square anthias, diamond goby, and a handful of hermit crabs and emerald crabs, so pretty heavy bioload. I still do my checks for phosphate (which is 0.02ppm according to the hana checker) and have never really checked for nitrates. I'm using the csc 250 skimmer and it works great for my system, although i think they have discontinued that model :sad: As for the DC pumps they are pretty good pumps, just thier controller power supplies are garbage, and to be honest when I had my dc pump i never once adjusted my pump level.

Chances are, you won't change the pump speed after initial setup as long as your bioload doesn't change. However, the advantage is in that initial tuning, being able to set it perfectly to your bioload. Easier than trying to exactly match a skimmer/pump to your bioload based on manufacturer's recommendations, no?

No :) I find that the water height and air intake are enough to perfectly tune for my needs, so I'd rather not buy a DC pump. More complicated, more stuff to break.

Fair enough. AC pumps are pretty much a known commodity too, you can generally size a skimmer based on the wattage/output of the pump

I plan the tank based on swimming room, and I think that has a lot to do with the bioload. The detritus needs to be extracted. The more fish you have laying waste, the more problems you could have.

If you were locked in a small room with a lot of people, that place is going to stink and cause you problems. Locked in a large room with a couple people, you're going to have a better time and waste management won't be an issue. If you are locked in a big room with a lot of people, but have a better waste removal solution, you will be a lot happier and only worry about that one dude who keeps eye balling your girl, as opposed to the carpets festering, and causing an ebola outbreak.

Double the skimmer for the tank size (400g on a 200g system) - carbon, gfo, waterchanges, rodi, and only feed the good stuff once a week (mysis, blood worms, etc.), flake once a day and nori once every other day.

I think as long as the system has good turn over, with proper flow to allow small particles and detritus to be caught up into the sump, then the rest is maintenance.

I had an understocked tank and fed three times a day, I had algae and high nutrients with an underpowered skimmer. So now I have an overstocked tank, feed less and skim more, and have no algae, no problems and perfect parameters. I also stopped dosing the unecessaries like reef roids, and other filter feeding material and now maintain better water quality.

Did you get your new skimmer Brad?:question: what are you getting if not
Barb

I have pumps coming in this week for the various bubble kings, I'll play with those for a while and see what I like. I might run dual BK 160s, maybe a 200. I have an Omega 150 and a Super Reef Octopus here to test. So not sure yet what I'll end up with.

I think it does address the question. Your question was how do you know if your tank has light, med, or high bioload: "How do we measure that? I mean, quantitatively, what's a medium bio load? Or heavy? Or medium light? "

So with a DO meter, measure your DO first thing in the morning before there is any light when DO is at its lowest levels. If DO is at 50% or less, you have a high bioload. If DO is 50-75%, you have medium bioload. If DO is 75%+, you have light bioload.

$150 is cheaper than many protein skimmers. Or rent one from a lab: http://www.google.ca/url?sa=t&rct=j&...2hTWDbiE64d4zQ

If your question was how to interpret a manufacturer's recommendation as to whether the skimmer is good enough for your bioload (once you've measured what it is), then nothing can of course resolve that since that is the manufacturer's recommendation. That is just up to the customer to trust the manufacturer and is simply a trust issue.