cryptic zone filtration

[cilyjr]

I have been doing a little experiment with some "alternative" ideas of filtration and reef keeping. These idea are based off of Steve Tyree’s ideas in multi-zone aquariums (second post will be an article on Mr. Tyree's theories) the basic idea is that there are naturally occurring zones in the ocean of varying light and current. The semi cryptic or “benthic zone” of Shawn Wilson’s naming, has been my first experiment.

Here you create an area of low filtered light and a reduced flow to promote the growth of filter feeding organisms that most often only get a small percent of space in the reef aquarium (i.e. behind and beneath rock work). The idea is; if these organisms are given a chance to thrive they act as biomechanical filtration. In my ‘fuge this area is created by using egg crate to form a shelf with several legs which hang down into the “Benthic” area. These will act as surface area for the sponges, squirts, and other life to anchor to. Above that a layer of rock rubble is placed. It allows for some flow and detritus to settle into the lower area of the design

On top of this, a layer of macro algae is placed. The nutrient exportation benefits of algae in the aquarium are well known, in our application the algae is our primary light filter. I use chaetomorpha as it grows quickly and is thick. This level should be shallow only a few inches deep. “The other reasons for a shallow (4-6") culture of algae is to optimize lighting and discourage die off. Conventional refugium design allows chaetomorpha to grow into a giant mass, with new growth at the surface where photosynthesis is possible, and older growth pushed deeper where light isn't available. This "old growth" is then allowed to slowly disintegrate and release its' nutrient catch (phosphate, silicate, nitrate, and heavy metals) back into the water column. Another poor practice is to harvest the algae at the top of the mass. This removes the efficient new growth, and leaves the dieing constituents behind.” Shawn Wilson

Overall this experiment has been a success for me. It is easy to see all the fan worms and small sponges growing on the glass. There are several feather dusters in the “Benthic” zone and I find new stuff every time I look.
The part of Mr. Tyree’s multi-zone experiment that I had been missing was the no light very low flow “Cryptic” zone. I have very limited space because 100% of my system must be hidden in the cabinet of my 46gallon display tank. The sump/fuge I have is an AGA 20 long. I chose this because it gave me the most room for the footprint. I have found some creative ways to use the space I have.

Since a large cryptic zone was out of the question for me I began thinking bout ways to employ some of the ideas. My first thought was to remove the top piece of egg crate and place PVC pipe side by side with small gaps to act in a similar manner as the egg crate shelf (I believe this idea to still have some merit) but I decided that 1’ PVC pipe would make the top zone too shallow or would take too much from the benthic zone. I will put this idea on hold for a future sump. My second was for a single 2inch piece of PVC. I was going pump water in using the return on my skimmer. I decided I didn’t like this idea for a few reasons. First being I had a hard time seeing the zone populating well with freshly skimmed water. Second the flow is very fast. Third I didn’t like the idea of using the PVC as once I sealed it I would not be able to look at what is colonizing inside without destroying it; my main purpose for doing all of this is experimentation. While browsing the isles at Lowes I came across this piece in the electrical area (see photo) since it has a removable piece held on with screws (I bought plastic screws to replace the metal ones) it would be easy to open it and see what is colonizing.

My next step was to find a way to allow water to be pushed through; I didn’t want it to be passive. The skimmer was out of the question so I decided to use the return pump. My return has a t valve allowing a portion of water to return to the sump to regulate flow in the display as I am sure many people do. I had not thought of using this at first because I do have UV attached to this line (how am I going to populate anything post UV) but I have not had the UV light plugged in for months. This also makes it the final zone water circulates through in the sump. Although the cryptic zone box is located in the first chamber of my sump, the water is coming from the pump that returns water to the display. I realize that the water makes a second trip through benthic area but I see no harm in that. I next purchased some Live Rock rubble, filled the electrical box with it, and sealed it up.

The rock will give the zone colonization a jumpstart and will be a place for animals to anchor. Now with the rubble sealed in, no light passes through the chamber. I checked by shining a flashlight in one side in a dark room. It is time hook it up. I used vinyl tubing and some barbed fittings. When I hooked it up I decided that the water flow was too strong to combat this I put holes in the tube which I may replace with a valve later. It is up and running

I realize due to the size of the cryptic that any real benefits in water quality will most likely be negligible; I am interested to see what life will colonize there. My plan is to open it every 6 months.

Thanks for reading this. Please feel free to comment or criticize, I welcome both

it has been a month since i have posted this thread in my local club forum and i will be opening the box soon to see if any colonization has begun.

 

[cilyjr]

an article explaining Mr. Tyree's ideas

Exploring the zones

Steve is a thinking man's reefkeeper. Most of us are content to enjoy observing the day-to-day happenings in our reef tanks and admire the many new forms of life that spring from the live rock, turning tiny crevices and the undersides of this vibrant living material into brightly coloured sponges, tunicates and tiny fan worm colonies. But not Steve. He is happier pondering the reasons for these explosions of life.

Early in his research, Steve discovered a scientific term "the gradient concept", which describes how marine life forms can be graded by the amount of light they receive to allow them to be categorised into different light zones. He decided to apply the same principles and come up with a series of zones that could be applied to reef aquariums.

"Traditionally," Steve explained, "scientists use three main physical parameters - light, water current and the type and amount of particulate matter suspended in the water column when describing the environmental conditions of the various natural tropical reef zones they have identified.

"The most commonly used zonal categories are defined as the Exposed and Semi-Exposed Zones. The Exposed Zone is described as a shallow water environment, which receives strong sunlight in the range of 10-100% of the light applying on the surface of tropical reef waters. These conditions are identical to light levels found on a shallow reef platform, where many of the light-requiring photosynthetic stony corals occur, and are representative of the conditions we try to attain in our stony coral captive reef systems.

"The water currents typical of this zone are in the order of 10-50cm per second, but can occur up to as high as 150cm per second. Organisms living in this zone need to have strong, dense structures to withstand such strong currents.

"Due to the strong water movement, large amounts of suspended particulate matter can also be found, but the over-powerful currents often prevent normal suspension feeding by filter feeding organisms from occurring.

"The Semi-exposed Zone is categorised in a similar manner, but light levels are lower, more in the order of 5-10% of the levels occurring at the surface. Water currents in these semi-exposed conditions range from 1-10cm per second, so organisms still require strong, dense structures to survive.

"Particulate matter remains suspended in the water column and allows passive filter-feeding organisms, like soft and hard corals, that can consume large to small particulates, to thrive.”

(Passive filter feeders are organisms that trap passing particulates by pumping water through their bodies.)

"The overall conditions in this zone are typical of lagoon reefs, back reef and deep reef conditions, and while the only photosynthetic organisms found are those that can tolerate low light conditions, a wide range of non-photosynthetic life forms can easily survive. Again, the conditions in this zone can be applied to captive reef systems and will be recognised by reef aquarists who operate deep tanks or employ lower than optimal light levels.”

While Steve recognises each of these classic natural reef zone categories in his own system, he was aware that there were other equally important zones that could be relevant to reef aquarium keeping that needed to be considered.

He finally came up with three more zones he regarded as principal elements for his own zonal-based reef modelling theory.

His first was defined as Semi-Cryptic and occurs in the deep lower sections of natural reefs or in reef areas with overhangs in shallow water. The main defining characteristics are very low light levels which would only support photosynthetic organisms that can survive in minimal light conditions.

The second is Cryptic and applies to the oft-called "twilight" zone of a reef, deep within caves or beneath the reef platform in shallow water. Incidental light is far too weak to support photosynthetic life forms.

Steve's third and final zone was the Filter Feeder Zone, a combination of the semi-cryptic and semi-exposed zones. The main feature is continuous water currents strong enough to keep medium to large particulate matter in suspension and available for filter feeding organisms.

In nature, this is the realm of gorgonian and non-photosynthetic soft corals. It is currently one of the biggest challenges to reefkeepers.

Back to basics

In order for there to be a clear understanding of these proposed new zones, Steve decided it was necessary to define what he meant by "cryptic".

He referred to biological dictionary terminology, which defines cryptic as an adjective referring to "organisms belonging to enclosed places and those organisms with a hidden mode of life". Good examples of these organisms can be found in a wide range of animal classes including corals, sponges, ascidians, hydroids, crustacea, molluscs and many more including whole families of fishes that live reclusive life styles.

Steve's three new zones needed to be defined in terms of the main parameters. He describes the Semi-Cryptic Zone as having light levels between 1% and 5% of those at surface level, with water currents in the order of 0.1-1cm per second, which allows only fine particulate matter to remain in suspension because of the weak water movement. Typically both passive and active suspension feeders are the major colonisers in this zone.

The Cryptic Zone has less than 1% of the light at surface level with currents less than 0.1cm per second. Only very fine particulate matter are suspended in the weak currents, and organisms develop very delicate structures and are dominated by active suspension feeders that generate currents through their feeding mechanisms.

Light has not a critical role to play in the Filter Feeder Zone and could vary 1-10% of the light levels on the surface. Similarly, a wide range of currents also could apply ranging from 1-10cm per second. The water would contain large amounts of suspended particulate matter and passive filter feeding organisms would thrive in these conditions.

Putting into practice

One of the main objectives was to see how this could be applied in a fresh approach to reef aquarium filtration which would use various types of cryptic organisms as a natural filtration process.

His first attempt involved a tri-zonal method of approach based on dividing a reef tank into three distinct zones arranged side by side. To the left of the tank was an exposed zone, which was the main viewing area and featured strong to low light intensity to support a wide range of photosynthetic organisms. Water currents varied from strong to low and contained large to medium particulate matter in suspension.

A filter feeder zone was located beside the exposed zone without any other form of physical barrier other than the sloping mound of live rock, which reached almost to the surface, to form a filter feeding channel.

No specific lighting was installed, and water pumped from the exposed zone provided a low to weak current. The water contained a wide variety of different-sized particulate matter.

Between the filter feeding zone and the next zone, Steve installed a black acrylic diffusion screen drilled with lots of holes of 3/16" diameter. This formed a cryptic zone where water from the filter feeder zone diffused through the screen, admitting only very fine grades of particulate matter.


Almost no light was admitted to this area, and all of the organisms were heterotrophic (requiring a supply of organic material, ie food, from the environment). As there was no plumbing in this area, water movement was minimal but the natural filtering effect was similar to that of a protein skimmer.

Steve’s next design employed a ⌦bi-zonal method with an acrylic diffusion screen dividing the tank into an exposed zone at the front with a cryptic zone behind.
As with the earlier approach, strong to low lighting was arranged at the exposed side, but precluded from the cryptic. Although designed on a two-zone basis, it should be recognised that semi-exposed reef conditions would also apply under and in-between the live rock.

Encouraged by his success with each of these methods, Steve decided to explore the commercial possibilities and designed a hybrid zonal method for use in his coral culturing business.

A series of coral frag-holding tanks, which we could call the Exposed Zone, were connected to three fully populated cryptic zone tanks with a compartment in-between containing two large 200-micron filter bags.

Water passed from the holding tanks through the mechanical filters and then into the cryptic tanks from where it passed through a protein skimmer before returning to the holding tanks. Steve was successful with thriving populations of cryptic organisms in the Cryptic Zone and good, healthy growths of frags in the holding tanks.

The organisms in his Cryptic Zone filters are varied, but sponges usually contribute the most in bioload terms. Sponge growth is quite remarkable, but as it can be harvested in a similar way to the caulerpas in an algae refugium as a means of exporting nutrients, large sponge populations are not a limitation.

Other organisms in the Cryptic Zone include sea squirts, bivalve molluscs, feather duster worms and foramiferans. Cryptic reef plankton also occurs, but it has been difficult to maintain pelagic plankton in captivity due, it has been theorised, to the pumps used to move water and generate currents damaging these delicate organisms.
Reef plankton differs from oceanic plankton in compromising two or three species of copepod.

Examples of the organisms used in Steve’s filter feeder zone filters include calcareous sponges, non-hermatypic corals, ascidians (Botryllus sp), thorny oysters and other bivalves and foramiferans.

As many of these are very decorative, there is no reason why the filter feeding zone could not form part of the viewing area of the tank.

Steve says most of the systems he’s designed and built have been for research or for production-based systems. He is looking forward to the next stage, designing and building marketable show tanks.

New designs are also in the pipeline for a Quad Zone system employing two diffusion screens, one with large holes, and a further screen with much smaller holes.

All of Steve’s methods have succeeded magnificently in terms of the health and growth of show tanks subjects such as coral and cryptic organisms like sponges and tunicates, and he is now looking towards captive spawning a whole range of cryptic organisms.
He is also hoping to push aside the barriers to keeping non-photosynthetic soft corals like the Dendronephthya species.

This article was first published in the Christmas 2004 issue of Practical Fishkeeping magazine.

 

[theJ]

Awesome dude, I cant wait to see whats growing in there in 6 months

 

[quibrzif]

Did the same, only in a separate 5g tank, fed by filtered water. Sponges grow well undisturbed, foraminiferans - worse, may be because the lack of food. Have no idea how to clean detritus, that started accumulate under the eggcrate. How to access it without disturbing the top layer? Same with cleaning the glass near eggcrate - not enough space for the glass scrubber.
The positive side is that it's truly refugium - not even snails to knock everything down.

 

[Gimpster]

You know those little starfish that every one hates... They like the dark and the ones I have are algea munchers, the micro brittle starfish I have eat the wastes as do my pods...

 

[class clown]

just would like to revive this thread up from the dead. I've been doing a little more reading on this lately and was wondering what your results have been. what have you observed in terms of water quality, stank stability, etc. your thoughts are appreciated.

 

[Frankie]

I to am interested in knowing how this has progressed. You put a lot of thought into it. Don't let the thread die here please.

 

[cilyjr]

i haven't opened the thing in a while.... i have upgraded my tank to a 90 with a 75 sump and the next step is to use a larger rubbermade tub....

 

[Jobiwan]

I've got an old Tenecor 60 from back n the 80's when built in wet/dries were all the rage, perfect for a crytic fuge, I put rubble in it and routed the sump return through it, did it a couple of years ago, it's packed with pods and sponges. I like it so much I incorporated a separate cryptic chamber in my current fuge setup, sponges are great natural filters...
Here's a photo of it, the fuge flow goes through the Chaeto chamber first in the hopes that detritus build up in the rubble will be lessened...
.
.

 

[cilyjr]

i have upgraded my system to a 90 gallon. i have a 75 gallon fuge now as well. i let the experiment die because i need time and money to get the new system up and running. now that it is done and i am settled in my new home; i decided it was time to revisit this. i learned some stuff from the first time around and am now working on a larger scale.

first off i will visit what i learned.

the true cryptic zone was not successful. i think this was because it was too tightly packed together with rock. secondly i think i was forcing too much water through it. when i opened it up the final time i did not see any real growth.

i do feel i gained much through the benthic zone portion of the experiment. i thin i had cleaner water in the old system.....

well here is my new ideas on the true cryptic zone...

here was the first cryptic note how much rubble was there

the new zone uses the egg crate from the benthic zone hopefully this will allow for more of the sponge growth

here it is with the lid....half of it has black plastic i figure the white lid will allow some very diffused light in.....cheato will be growing over the top of it as well

finally here is a picture of my sump ( i have a fish room now) i had a compact florescent light for the last few months...with just a ball of cheato...i did not get much growth with the lights so i switched back to the 5000k bulbs that i had success with before

 

[trido]

Thanks for the update. I have recently built a benthic rack for my sump similar to the one you have posted above. I like your new cryptic system much better than the last one. Please keep us updated on the whole set up this time around

 

[SpicyMcHagis]

Very interesting setup, I cant wait to see the next update.

 

[cilyjr]

Thanks for the update. I have recently built a benthic rack for my sump similar to the one you have posted above. I like your new cryptic system much better than the last one. Please keep us updated on the whole set up this time around

alot more room in a 75 gallon sump to play with than i had in the 20long sump before

 

[Frankie]

Cool I am glad you did not give up. It will be interesting to see what you grew in there after some time.

 

[jeffkeith_us]

Water Flow and Light

I don't think this one is going to give you what you want either. Algae really need a ton of red spectrum and the cryptic species need slow flow so that they can eat the small POM out of the water. Water flow so slow that only the smallest POM will stay in the water column. Fan worms need POM that will fit in their feed grove and sponges starve if large POM or anything else for that matter clogs their intakes.

 

[jeffkeith_us]

Sea Sponges

Sea sponges are the simplest form of multi-cellular animals. A sponge is a bottom-dwelling creature which attaches itself to something solid in the sea bed and filter nutrients from the water that they force through their porous bodies with flagella. The scientific name for sponges is "Porifera," which translates into "pore-bearing." A sponge has differentiated cells and functionally distinct layers. Because of the lifestyle they lead, sea sponges do not need, and therefore lack, nerve cells, muscle cells and internal organs of any kind. The ameobocytes secrete spicules which stack up together to make the sponge.
Sponges have no true circulatory system; instead, they create a water current which is used for circulation. Dissolved gases are brought to cells and enter the cells via simple diffusion. Metabolic wastes are also transferred to the water through diffusion. Sponges pump remarkable amounts of water.
Leuconia, for example, is a small leuconoid sponge about 10 cm tall and 1 cm in diameter. It is estimated that water enters through more than 80,000 incurrent canals at a speed of 6cm per minute. Leuconia has more than 2 million flagellated chambers whose combined diameter is much greater than that of the canals, water flow through chambers slows to 3.6cm per hour. Such a flow rate allows easy food capture by the collar cells. All water is expelled through a single osculum at a velocity of about 8.5 cm/second: a jet force capable of carrying waste products some distance away from the sponge.
Never take a sponge out of the water, never. The jets can’t re-prime if you get almost any amount of air in the pore and the sponge will starve. Cryptic sponges can and do eat algae, but if you expose them to light algae will grow inside this animal and again clog the water paths within and the end result is the same.

 

[jeffkeith_us]

Sea Sponge Reproduction
First of all Ses sponges can reproduce sexually or asexually.
Asexual reproduction is through internal and external budding. External budding occurs when the parent sponge grows a bud on the outside of its body. This will either break away or stay connected. It goes without saying that an asexually reproduced sponge has exactly the same genetic material as the parent.
In sexual reproduction, sperm are dispersed by water currents and enter neighboring sponges. All sponges of a particular species release their sperm at approximately the same time. Fertilization occurs internally, in the mesohyl. Fertilized oocytes develop within the mesohyl. Cleavage stages are highly varied within and between groups, sometimes even within a single species. Larval development usually involves an odd type of morphogenetic movement termed an inversion of layers. When this occurs in some species (for example, in Sycon coactum), the larva flips into the choanocyte chamber, and then can emerge via the water canal system and out through the osculum.
Although sponges are hermaphroditic (both male and female), they are not self-fertile. Most sponges are sequential hermaphrodites, capable of producing eggs or sperm, but not both at the same time.

 

[jeffkeith_us]

Fan Worm, Feather Duster Worm (Annelids)
The plume of Fan Worms can measure up to 10" in diameter on some species, while the worm may range from 2" to 7" long. Primitive eyes allow the worm to quickly withdraw its plume if it detects motion (usually a predator). Which makes them efficient filter feeders that play an important role in a properly balanced reef system.
Fan Worms are marine segmented worms that are sessile, attached to the substrata by their base and can be quite attractive depending on the type. They are a member of the phylum Annelida, which also includes earthworms. Fan Worms are usually of the families Terebellidae (Medusa Worms), Sabellidae (Feather Dusters), or Serpulidae (Christmas Worms). While their close cousins the mobile (Errantia) bristleworms have a body with equal segments (metameres), the sessile bristleworms (Sedentaria) will have body segments of different sizes. Found in nearly all tropical regions of the world, Fan Worms will produce parchment, a skin-like casing made from body secretions, as they burrow into the substrate of choice. Christmas Worms position themselves in such a way that their "host" coral grows completely around the worm, with only its plume (radiole) crown visible. Other fan worms build small calcareous tubes attached to hard substrates most likely LR or coral.
Fan worms are never bad in either display aquarium, cryptic filter, sump, or the refugium. They exist in virtually every reef tank and earn a living by filtering the water through their fan to collect small foods to eat. Growth and proliferation of fan worms indicates that there is enough POM of the correct size in the water column to support them.
Being heterotrophic not autotrophic or photosynthetic they must catch their food to survive. Tanks that have little or no protein skimming, higher bio-loads, either have or are fed zooplankton, and those which are fed small foods such as phytoplankton will tend to have more fan worm growth. Even in a fully stocked mature reef aquarium, Annelida do still require some supplemental food source yet will feed happily upon the available detritus, plankton (of all kinds), and bacteria. Because you are keeping in an environment in which supplemental feeding is necessary, use infusoria, vitamins, and foods designed for filter-feeding invertebrates.
They also are food for other animals such as Copperbanded Butterfly fish and so need to be protected. The ideal substrata for Fan Worms is one with plenty of live rock, a sand bed, and invertebrate friendly inhabitants. Feather Dusters should not be kept in reef tanks with Angelfish or Butterflies, which prey on them.

 

[jeffkeith_us]

Scallops & Oysters
Members of the bivalve class, scallops, oysters, and mussels belong to the Limidae, Pectinidae, Ostreidar, and Mytilidae families. All have a two-part shell with a hinge and foot, and have no true head. Found in most marine environments, those that burrow into the substrate usually have an enlarged foot and one intake and one exhalant siphon. Oysters have a smaller foot and secrete byssal threads that anchor them to rocks or other structures. While they are not considered social, they are often found in large clusters of individuals.
Like the true oysters, scallops have a central adductor muscle, and thus the inside of their shells has a characteristic central scar, marking the point of attachment for this muscle. The adductor muscle of scallops is larger and more developed than that of oysters, because they are active swimmers; scallops are in fact the only migratory bivalve. Their shell shape tends to be highly regular.
Most scallops are free-living, but some species can attach to a substrate by a structure called a byssus, or even be cemented to their substrate as adults (e.g. Hinnites spp.). A free-living scallop can swim, by rapidly opening and closing its shell. This method of locomotion is also a defense technique, protecting it from threatening predators.
Some bivalves have primitive eyes located along the edge of the mantle or at the ends of the siphon. These eyes are always blue, and they respond to light and shadows.
They require a sandy substrate or a large rock formation to find comfortable spots to rest and feed. Specialized foods and pristine water quality are required to successfully maintain these organisms in the home aquarium.
Cryptic bivalves are also mixotrophic filter feeders, requiring “hodgepodge” of POM as food supplemented with feeds designed for these types of invertebrates and are able to absorb nutrients right out of the water. They do not farm Zooxanthellae and this makes them somewhat more demanding in the home aquarium than their cousins the Tridacnid, however.