Are Skimmers a necessity?

[Timfish]

Whith all the research across many fields of science showing how critical healthy microbiomes are for the survival of both ecosystem and individual organisms why would you consider arbitrarily removing a subset of a systems microbiomes would be beneficial to long term survival of either?

 

[ReefGeezer]

Whith all the research across many fields of science showing how critical healthy microbiomes are for the survival of both ecosystem and individual organisms why would you consider arbitrarily removing a subset of a systems microbiomes would be beneficial to long term survival of either?

Aren't the microbiomes you speak of not so much waterborne? Would a skimmer have direct impact on them? It could limit organics too much I suppose. That can be controlled though.

I think a skimmer can serve two purposes...
1. Conditions must be suitable for microbiomes to be established. I think skimmers can be a good tool to establish and maintain those conditions until biological processes become robust enough to do the job themselves.
2. Even when those biological processes are operating well, a properly operated skimmer can provide an additional nutrient processing pathway that allows for heavier bioloads.

 

[Randy Holmes-Farley]

Whith all the research across many fields of science showing how critical healthy microbiomes are for the survival of both ecosystem and individual organisms why would you consider arbitrarily removing a subset of a systems microbiomes would be beneficial to long term survival of either?

Is there any evidence that this happens and is detrimental?

If there was a general observation that folks using skimmers had some sort of problem that people without skimmers did not have, that might be one possible reason, but the reverse is equally true relating to pathogenic microorganisms. Neither, however, has data to support it that I have seen.

Lots and lots of things we do impact the various microorganisms in the aquarium.

 

[Crustaceon]

The math would indicate if nutrients are being “stripped” it isn’t the weekly 10% water changes, something else is occurring. But not sure what strip means in this context.

I'll put it into context: I'm not saying nutrients are at absolute zero, which isn't going to be the case with carbon dosing or aggressive turf scrubbing either. What i'm saying is nutrients are undetectable on a hanna checker for enough time to cause all kinds of low-nutrient related issues. This is without running a skimmer, or any other nutrient reduction method. Not even marinepure bricks or similar. All tangs were fat, happy and growing so they weren't being underfed. I had to dial that system's water changes back to a weekly 5% in order to have detectable nitrate levels. I did have some decently-sized acro colonies but nothing large enough to deplete N&P on their own. This all came after removing the skimmer... then chaeto and finally just doing water changes to maintain trace levels but having to balance change % to stay above 2ppm nitrates after seeing everything go pastel and observing base recession in a few colonies. Anything below 2ppm and that tank developed loads of issues.

 

[Crustaceon]

Whith all the research across many fields of science showing how critical healthy microbiomes are for the survival of both ecosystem and individual organisms why would you consider arbitrarily removing a subset of a systems microbiomes would be beneficial to long term survival of either?

I think they do remove some of that healthy biome but those organisms (typically bacteria) easily reproduce fast enough to offset those losses. I'm more curious how skimmers impact larger "free floating" fauna in a larval state. This especially has my curiosity since I'm more focused on rock flower anemones now and hope for lots of babies through "natural processes" (cough cough) that could theoretically be impacted by a skimmer.

 

[HBtank]

I'll put it into context: I'm not saying nutrients are at absolute zero, which isn't going to be the case with carbon dosing or aggressive turf scrubbing either. What i'm saying is nutrients are undetectable on a hanna checker for enough time to cause all kinds of low-nutrient related issues. This is without running a skimmer, or any other nutrient reduction method. Not even marinepure bricks or similar. All tangs were fat, happy and growing so they weren't being underfed. I had to dial that system's water changes back to a weekly 5% in order to have detectable nitrate levels. I did have some decently-sized acro colonies but nothing large enough to deplete N&P on their own. This all came after removing the skimmer... then chaeto and finally just doing water changes to maintain trace levels but having to balance change % to stay above 2ppm nitrates after seeing everything go pastel and observing base recession in a few colonies. Anything below 2ppm and that tank developed loads of issues.

I wasn’t commenting on your or any specific tank, simply that water changes are not the most effective option for dealing with elevated nutrients…. IF that is a problem.

 

[Crustaceon]

I wasn’t commenting on your or any specific tank, simply that water changes are not the most effective option for dealing with elevated nutrients…. IF that is a problem.

And you’re absolutely correct. It’s actually really inefficient at reducing grossly elevated levels which is why I see it as more of a proactive method well before high nutrients become a problem. Generally you don’t want to have to do large water changes back to back to go from let’s say 50ppm nitrates to 10ppm when carbon dosing and a skimmer do a far more efficient and cost effective job of getting the desired end result.

 

[Timfish]

I think they do remove some of that healthy biome but those organisms (typically bacteria) easily reproduce fast enough to offset those losses. I'm more curious how skimmers impact larger "free floating" fauna in a larval state. This especially has my curiosity since I'm more focused on rock flower anemones now and hope for lots of babies through "natural processes" (cough cough) that could theoretically be impacted by a skimmer.

It may seem a reasonable assumption bacterial populations are stable long term but this paper shows there can be significant changes in numbers in a tightly controlled system with stable physical and chemical Parameters:

https://journals.asm.org/doi/10.1128/AEM.00179-18

Larval survival certainly is a concern. I doubt I would have any success with these clams using the "standard" equipment used in most reef systems.

 

[Timfish]

Is there any evidence that this happens and is detrimental?

If there was a general observation that folks using skimmers had some sort of problem that people without skimmers did not have, that might be one possible reason, but the reverse is equally true relating to pathogenic microorganisms. Neither, however, has data to support it that I have seen.

Lots and lots of things we do impact the various microorganisms in the aquarium.

So far, teh only paper (which we've discussed before on RC) I've found looking specifically at how skimmers alter microbiomes in reef aquaria is Feldman, ea al, paper Bacterial counts in Reef Aquaria which showed skimmers do significantly alter microbiomes. "Thus, skimming inadvertently provides severe (?) evolutionary pressure to skew the tank’s resident water column bacteria population to favor the “non-skimmable” cohort." SOme may consider this a bias on my part but inadvertantly altering something so essential as the microbiomes in a system without being able to quantify what is happening seems to me something to be avoided.

But you're right, We don't have any research specifically showing skimmers directly promote pathogenic OR beneficial microbiomes. There is research like this paper linking reduced diversity with compromised immune system in corals. We also have a lot of research in other fields showing disrupting microbiomes has severe ramifications. In extreme killing the host organism or ecosystem. Notable examples are the thousands of people dying every year after antibiotics disrupt their microbiomes which lets Clostridioides difficile (1) (2) take over and the world wide concern over unsustanable farming practices literally sterilizing farmland.

As far as what I've observed I'd ahve to agree with the concern expressed by the researcher in this paper "Although captive breeding and propagation of corals is a well-known activity among aquarium hobbyists and public aquariums, the link between coral science and aquaculture is still poorly developed". Reef aquarists are being advised to do things that are not supported by the available research or even contraindicated.

I certainly agree, there's lots of things we do that impact the various microorganims in our systems. But the organisms and microbiomes in our systems are impacting each other and we can't test for these processes. Sadly we very much need research giving us a better understanding of what is happening and how to quantify these processes. Until then ignoring the warning signs given by resaerch in other fields doesn't seem wise to me.

 

[Randy Holmes-Farley]

So far, teh only paper (which we've discussed before on RC) I've found looking specifically at how skimmers alter microbiomes in reef aquaria is Feldman, ea al, paper Bacterial counts in Reef Aquaria which showed skimmers do significantly alter microbiomes. "Thus, skimming inadvertently provides severe (?) evolutionary pressure to skew the tank’s resident water column bacteria population to favor the “non-skimmable” cohort." SOme may consider this a bias on my part but inadvertantly altering something so essential as the microbiomes in a system without being able to quantify what is happening seems to me something to be avoided.

But you're right, We don't have any research specifically showing skimmers directly promote pathogenic OR beneficial microbiomes. There is research like this paper linking reduced diversity with compromised immune system in corals. We also have a lot of research in other fields showing disrupting microbiomes has severe ramifications. In extreme killing the host organism or ecosystem. Notable examples are the thousands of people dying every year after antibiotics disrupt their microbiomes which lets Clostridioides difficile (1) (2) take over and the world wide concern over unsustanable farming practices literally sterilizing farmland.

As far as what I've observed I'd ahve to agree with the concern expressed by the researcher in this paper "Although captive breeding and propagation of corals is a well-known activity among aquarium hobbyists and public aquariums, the link between coral science and aquaculture is still poorly developed". Reef aquarists are being advised to do things that are not supported by the available research or even contraindicated.

I certainly agree, there's lots of things we do that impact the various microorganims in our systems. But the organisms and microbiomes in our systems are impacting each other and we can't test for these processes. Sadly we very much need research giving us a better understanding of what is happening and how to quantify these processes. Until then ignoring the warning signs given by resaerch in other fields doesn't seem wise to me.

Yes, Ken’s tests say nothing about whether skimmers are detrimental to the microbiome.

 

[Randy Holmes-Farley]

Your point about many processes we use possibly being detrimental to breeding of inverts due to larval damage is certainly worth considering.
Few reef tanks successfully breed corals. Would people be more successful in breeding without high shear pumps, skimming, UV, etc. is worth consideration.