Why do we need filters in a reef?

[reefprobe]

I have a 10 gallon tank loaded with rock ,live sand ,critters ,starfish,clownfish,fire fish,a bunch of coral frags. The tank has absolutely no filtration! The only thing in the tank running is a small 120gph pump. And it's not my tank it's my sons ....he has a kick butt t-5 light. Anyway the tank has been doing great for a couple of months were adding fish and coral/inverts weekly and we don't see any reason to add more filtration? I have had tanks in the past with and without skimmers still not convinced they help? Outside of water changes and supplements why add more filters to a balanced system...
I will be posting a pic or video soon

 

[duke62]

with a 10 gallon it is easier to control things if anything gets out of wack.if your nitrates and phosphates get out of control a 3 to 4 gallon water change with matching ph,cal and alk to match whats in the tank so there is no shock to the corals is alot easier then if you have a 100 gallon system and you need to make a huge water change.the skimmer is helpful in this case.it will remove what a large water change can do without ruining the chemistry in the tank along with a carbon and phos reactor.if you have corals which can handle dirtier water like shrooms and zoas it can work but more sensitive corals probably wont handle it as well

 

[reefprobe]

I have a 10 gallon tank loaded with rock ,live sand ,critters ,starfish,clownfish,fire fish,a bunch of coral frags. The tank has absolutely no filtration! The only thing in the tank running is a small 120gph pump. And it's not my tank it's my sons ....he has a kick butt t-5 light. Anyway the tank has been doing great for a couple of months were adding fish and coral/inverts weekly and we don't see any reason to add more filtration? I have had tanks in the past with and without skimmers still not convinced they help? Outside of water changes and supplements why add more filters to a balanced system...
I will be posting a pic or video soon

http://youtu.be/pKILKSHhcFc


It may look like the tank is a little dark/yellow but my iphone isn't the greatest and the room light is yellow. If anyone wants to see a vid with the LED's on and lights off in the room let me know. I will also be planning to put my other tanks on my You Tube account soon so you guys can see them.

 

[Chris Jury]

I wouldn't add any biological filtration as the microbes and critters growing on/in the sand and rock should do that very effectively. Other forms of filtration such as protein skimmers, granular activated carbon (GAC), granular ferric oxide hydroxide (GFO), etc. can all be very useful for removing certain substances from the water, improving water quality.

If we compare our aquariums to nature we see that most tanks have a far, far higher density of fish than in nature, and hence a higher production of fish waste than in a comparable area in nature and larger need for nutrient processing as a result. Just to give a ball-park idea of realistic fish densities compared to natural reefs: a recent study in PNAS found that on healthy, essentially unfished reefs in the Indian ocean the biomass of fish is about 1000-1500 kg/hectare of reef. Scaling that down to an aquarium, that would be about 4-6 fish about 3-3.5" long in a 120 gal aquarium (or maybe one 5-6" fish). Most folks keep a lot more fish than that.

The far bigger issue, however, is the relatively short residence time of water on coral reefs as compared to in our tanks. On a normal reef the water residence time is typically about 2-12 hrs, depending on the reef and wind, primarily, which drives waves and water over the reef. This means that reefs in nature get essentially a 100% water change about 2-12 times per day. Excesses of waste or other material are quickly washed away and ultimately remineralized elsewhere. Most reef tanks get, what, maybe a 10% water change once per week to once per month? Excess waste material and other nasty substances that are simply washed away from the reef and processed elsewhere can easily and rapidly build up in a reef tank. As a result it is often necessary to use filtration equipment (skimmers, GAC, GFO, etc.) to remove these excess wastes to keep the tank running well. Exactly what sort of filtration is required or at least useful varies from tank to tank, depending on the individual situation.

Reef tanks are somewhat of a hybrid between natural reefs and wastewater treatment plants. In many ways they operate similarly to natural reefs, but we also put dramatically higher demands on the natural filtration capacity by (usually) stocking higher densities of fish than are natural, and by performing dramatically less in terms of water changes. For these reasons, we often need equipment to help us achieve healthy conditions.

cj

 

[MIKE NY]

I wouldn't add any biological filtration as the microbes and critters growing on/in the sand and rock should do that very effectively. Other forms of filtration such as protein skimmers, granular activated carbon (GAC), granular ferric oxide hydroxide (GFO), etc. can all be very useful for removing certain substances from the water, improving water quality.

If we compare our aquariums to nature we see that most tanks have a far, far higher density of fish than in nature, and hence a higher production of fish waste than in a comparable area in nature and larger need for nutrient processing as a result. Just to give a ball-park idea of realistic fish densities compared to natural reefs: a recent study in PNAS found that on healthy, essentially unfished reefs in the Indian ocean the biomass of fish is about 1000-1500 kg/hectare of reef. Scaling that down to an aquarium, that would be about 4-6 fish about 3-3.5" long in a 120 gal aquarium (or maybe one 5-6" fish). Most folks keep a lot more fish than that.

The far bigger issue, however, is the relatively short residence time of water on coral reefs as compared to in our tanks. On a normal reef the water residence time is typically about 2-12 hrs, depending on the reef and wind, primarily, which drives waves and water over the reef. This means that reefs in nature get essentially a 100% water change about 2-12 times per day. Excesses of waste or other material are quickly washed away and ultimately remineralized elsewhere. Most reef tanks get, what, maybe a 10% water change once per week to once per month? Excess waste material and other nasty substances that are simply washed away from the reef and processed elsewhere can easily and rapidly build up in a reef tank. As a result it is often necessary to use filtration equipment (skimmers, GAC, GFO, etc.) to remove these excess wastes to keep the tank running well. Exactly what sort of filtration is required or at least useful varies from tank to tank, depending on the individual situation.

Reef tanks are somewhat of a hybrid between natural reefs and wastewater treatment plants. In many ways they operate similarly to natural reefs, but we also put dramatically higher demands on the natural filtration capacity by (usually) stocking higher densities of fish than are natural, and by performing dramatically less in terms of water changes. For these reasons, we often need equipment to help us achieve healthy conditions.

cj

excellant anyalsis .....should be a sticky in the beginners forum

 

[tosiek]

Ontop of what Chris said your tank inhabitants are alot hardier than you would expect, especially with what your keeping in your tank which are the more hardy of coral and fish. Fish/coral have a range that they want all the parameters to be at and if you keep in their range they should be happy You don't need 0.00 Po4, you can get away with 0.03 or so and not see any negative affects for a long time aside from some algae popping up every once in a while.

Its completely possible to just utilize the natural filtration and whatever water changes you do every week to keep a stable and nice tank. Noone ever said you "needed" a skimmer or run carbon or phosban. It is a big plus if you can though and certain coral just won't flourish in a tank with no filtration. I doubt you could keep some of the more delicate SPS in that tank without them going brown and ugly while the hardier of SPS will grow and color up and be happy in your tank.

There's alot of nano tank owners that just rely on WC's and its possible. Its alot harder on larger tanks though to just do WC's and keep the more demanding of coral.

 

[basiab]

Actually many corals like it when the water is not scrubbed clean. But now comes the tricky part. You have a good balance now and you are about to change it by adding another fish. If within a few weeks you see unwanted algae you will know you tipped the balance.
Did you do a search here for info? You can probably find more info on filterless tanks on wetwebmedia.com.

 

[Chris Jury]

Actually many corals like it when the water is not scrubbed clean. But now comes the tricky part. You have a good balance now and you are about to change it by adding another fish. If within a few weeks you see unwanted algae you will know you tipped the balance.
Did you do a search here for info? You can probably find more info on filterless tanks on wetwebmedia.com.

Agreed, and therein lies the rub. An unfortunate consequence of many types of filtration (especially protein skimmers) is that they remove things we don't necessarily want them to remove (or at least more than we want them to remove) while they are removing the things we *do* want them to remove. All corals need food, though some are more flexible about how much they require than others, and they all need clean water free of nasty, dissolved compounds. Skimmers remove some nasty compounds, which is good, but they also remove particles. In many tanks this isn't a problem with most corals, but in heavily filtered, sparsely fed tanks (which are becoming more and more common) it is defintely possible to remove so much particulate material that the corals literally starve. Ninety nine times in 100 when people complain about pale or pastel corals in their tanks (especially common in zeovit style tanks, but not exclusively) the problem is that the corals are not getting enough food, are starved for nutrients and calories both, and their pigments, both coral and zooxanthellae pigments, take a hit as a result.

Corals require both enough food and clean water, as do all other organisms in the tank. Achieving both in a tank at the same time is 90% of what is involved in keeping a successful reef tank. Almost everything we worry about in our tanks really comes down to achieving a successful balance of keeping everything adequately fed and the water adequately clean.

cj