DEBATE: Skimmers Yes or No

[FishyDP]

I have 3 small tanks all running without skimmers, sumps or refugium 2 of which are nearly 3 years old and the 3Rd is an evo 13.5 that's a year nearly. In such small tanks I can't get an efficient enough skimmer that isn't massive. All tanks are run on natural sea water and I only do a water change every 6-8 weeks of 10%. The only filtration I have on them is a bit of filter floss and biohome media. No carbon or gfo.

The 1St is a 90litre,2nd is 35l and the 3Rd is an evo13.5.

Bravo! Great to see successful, simple systems ran like this.

 

[SynGraves]

Never ran a skimmer personally. Never saw a reason to run a skimmer on my 20g long reef and now my 10g nano reef. I just make sure to cycle the tanks properly and do weekly or bi-weekly water changes. Never add too much live stock at once is always a good habit to get into as well.

 

[malacoda]

For the people who are skimmerless, how do you get rid of any metals that enter your tank from food, equipment, etc? Just curious. There are all kinds of shapes and forms that are not detected in IC/ICP testing.

Speaking for myself I don't know that I am, or am not, getting rid of any metals in my tank. I've been running my 24g skimmerless for 9 months now. Prior to that I was using a Tuzne 9001 for about 10 months - skim was always wet and weak-tea colored. So while it was doing something I can't say it was doing much.

Anyways, I still use floss which I replace weekly. Matrix Carbon and Phosguard which I replace every 6 months (or when I notice water getting a slight yellow tinge in my white water change buckets). And I still do a monthly 20% water change.

To what extent are metal present in my tank? I don't know.

To what extent were they present during the 10 months I was skimming? No idea.

Are my floss and/or carbon capturing and removing those metal to a significant extent? Don't know.

Are bacteria or other micro-organisms processing or stabilizing said metals? Do they even have the capacity to (as some brownfield bacteria do)? I have no idea.

Tank is healthy and happy. So I'm honestly not going to worry about it.

Besides, if even IP/ICP testing can't detect all metals, then how can one know if skimming is removing said metal to a significant extent?

My humble opinion: skimmers are a choice, not a necessity. You can also chose other means or combinations of mechanical, biological, and/or chemical filtration and still have a happy, thriving tank.

 

[Scrubber_steve]

For the people who are skimmerless, how do you get rid of any metals that enter your tank from food, equipment, etc? Just curious. There are all kinds of shapes and forms that are not detected in IC/ICP testing.

Algae filtration (scrubber), GAC, & water changes. But then the heavy metals are added back via AquaForest trace element dosing LOL

 

[Nicholas Dushynsky]

Bravo! Great to see successful, simple systems ran like this.

Thanks, I think the thing is with them is they are all low stocked I.e. Only 2 fish in the 2 smaller tanks and only 3 in the bigger one. So only small fish with low waste helps alot.

 

[Scorpius]

I like having a skimmer because I can use it to inject fresh oxygen from outside to combat Co2/low ph issues I have in winter time.

 

[HexaReef]

I personally dont run a skimmer. I have a 40g breeder dispay, with a 10g sump. Only thing in my sump is a filter sock, sand, heater, and uv filter. I had a skimmer, but for months my corals looked lame and wouldn't grow. Took the skimmer out and BOOM, coral growth started taking off. My overflow oxygenates my water and my method of export is 10% WC'S ever month.

I have 6 fish, 2 hermits, 1 conch, and 1 turbo. I feed once per day.

Wont say that ill never use a skimmer in the future, but not anytime soon.

I did some research and found skimmers to be very "bioload" dependent. Meaning, if you have a few fish in a reasonable sized tank with modest feeding, then water changes are all you should need for export method. But, if you have an overstocked tank and feed more frequently, maybe a skimmer is the best way for export and to reduce the cost of waterchanges.

All-in-all, i dont believe it to be a necessity, rather a convenience tool.

 

[Timfish]

No. Skimmers are superfluous at best and may be antithetic to keeping reef systems for the decades or centuries they should live . Cryptic sponges remove labile DOC ~2000x faster than anything else. (On reefs the labile component of DOC is roughly 1/3 of total DOC, refractory DOC is roughly 2/3s.) As phototrophs/mixotrophs, corals are the best choice for nutrient cycling in reef systems and are competing with algae for nutrients. I haven't found any research showing skimmers remove the Dissolved Combined Neutral Sugars (DCNS) that promotes heterotrophic microbial processes potentially pathogenic to corals.

Here's four skimmerless systems:

 

[sawdonkey]

No. Skimmers are superfluous at best and may be antithetic to keeping reef systems for the decades or centuries they should live . Cryptic sponges remove labile DOC ~2000x faster than anything else. (On reefs the labile component of DOC is roughly 1/3 of total DOC, refractory DOC is roughly 2/3s.) As phototrophs/mixotrophs, corals are the best choice for nutrient cycling in reef systems and are competing with algae for nutrients. I haven't found any research showing skimmers remove the Dissolved Combined Neutral Sugars (DCNS) that promotes heterotrophic microbial processes potentially pathogenic to corals.

But what amount of cryptic sponges do you need to effectively filter DOCs? Where do you get them, and can a typical aquarium keeper keep enough of them thriving to keep your water clean? I’m not trying to disprove what you’re saying because I’m a ”skimmer guy.” I honestly like this idea, but I’m not sure it’s feasible in aquariums? I’d like to see this in practice.

I use a skimmer because I need really clean water for my SPS and I have some really dirty fish (among others, two large triggers and a 3.5 ft long moray that’s as thick as two garden hoses). I also employ biopellets AND dose NOPOX sometimes. I still can’t get NO3 below 10! I go with the heavy import heavy export method.

 

[Fourstars]

For the people who are skimmerless, how do you get rid of any metals that enter your tank from food, equipment, etc? Just curious. There are all kinds of shapes and forms that are not detected in IC/ICP testing.

Algae and carbon and water changes.

 

[paul barker]

when I had my 75 gallon fish only tank I had 120 lbs of live rock and a 4 inch sand bed and 3 Emperors 400 that all the ran great for ten years

 

[Jay Z]

I run one.

Personally I think its application specific or preference.

 

[Mortie31]

One very important thing a skimmer does is oxygenate the water.

Without a skimmer I would say it would be very hard to get pH above 8.1 without some other way of elevating it

What if the CO2 in your house is high, skimming would drive the ph down.. that’s why people run airlines outside or use CO2 scrubbers. The amount a skimmer affects O2 levels is entirely dependent on the quality of the air in your house and the differential between the O2 in the air and your tank..

 

[Mortie31]

Does anyone know of any analysis done on what a skimmer actually does remove? If so please link the research

 

[Jay Z]

What if the CO2 in your house is high, skimming would drive the ph down.. that’s why people run airlines outside or use CO2 scrubbers. The amount a skimmer affects O2 levels is entirely dependent on the quality of the air in your house and the differential between the O2 in the air and your tank..

Heat recovery ventilator (fan tech) Brings in fresh air to your house, expels stale air, stale air heats incoming air.

keeps my co2 levels around 400, outside is around 350. My skimmer is plumbed into this.
With it off I'm around 850. Just me and my dog, so co2 levels are low to begin with.

 

[Mortie31]

Heat recovery ventilator (fan tech) Brings in fresh air to your house, expels stale air, stale air heats incoming air.

keeps my co2 levels around 400, outside is around 350. My skimmer is plumbed into this.
With it off I'm around 850. Just me and my dog, so co2 levels are low to begin with.

Cool nice system... but your situation is very unusual most dont have heat recovery systems...

 

[Jay Z]

Cool nice system... but your situation is very unusual most dont have heat recovery systems...

it was installed for health reasons, skimmer hooked to it was just a bonus.

 

[hart24601]

What do skimmers do?
-They remove organics, dissolved & particulate.
But not very well in comparison to activated carbon. A skimmer will remove around 30% of post feeding DOC where as GAC can remove up to 80%.

- They oxygenate the water?
No they don't. They inject air into the water. If that >>air<< happens to have high levels of CO2 (indoors co2 can get up to 3,000ppm), and/or pollution (supposedly fresh air drawn from outside can contain air borne pollution delivered from near & far), that's what they inject into the water.
Only photosynthesis creates O2, from CO2 - algae filtration for example.

I hear that 30% vs 80% number a lot and think that is based out of an advanced aquarist article, but I would like to see that revisited. The amount my skimmer has pulled out while also running carbon and purigen is pretty amazing. Now I know skimmers also remove larger items like bacteria but it seems to me there must be something more going on. Perhaps more examination of what all skimmers remove.

I recently expanded my sump, display is 34g and I removed the 10g tank sump and plumbed downstairs to a Rubbermaid. Around 100g more volume. New salt water. I had a small skimmer along with purigen and carbon, which I change a lot and was still active as I did a dye test after I noticed the following.

With the new sump I Installed a large skimmer, somatic 120 (vertex 180i) and in just a couple nights it pulled the below image. Keep in mind this is a big skimmer cup and really it was about 20g tank water and 100 new. Carbon not exhausted nor purigen. Leads me to think there is something substantially more than that 30% number going on in our tanks. Not arguing what they found, just I think we need to explore that more.

 

[jda]

Dr. Holmes-Farley has some articles on skimmers and what they pull out. Organics, mostly... which also bind all kinds of other things which get removed too.

 

[Mortie31]

The advanced aquarist article someone mentioned earlier...
https://www.advancedaquarist.com/2010/2/aafeature
And there conclusion
The chemical/elemental composition of skimmate generated by an H&S 200-1260 skimmer on a 175-gallon reef tank over the course of several days or a week had some surprises. Only a minor amount of the skimmate (solid + liquid) could be attributed to organic carbon (TOC); about 29%, and most of that material was not water soluble, i.e., was not dissolved organic carbon. The majority of the recovered skimmate solid, apart from the commons ions of seawater, was CaCO3, MgCO3, and SiO2 - inorganic compounds!