The inevitable nano crash.

[skylsdale]

Alright, I'm sure most of you are aware of some of the current reefkeeping events regarding people pulling out their DSB's and such. Those who have had them up and running for the last 4-5 years are experiencing the fallout of total sandbed and LR absorption. One of the telltale signs they have experienced is the hair and nuisance algaes that begin to establish because of the nutrients seeping from the DSB and LR.

This morning I was cruising through some threads at N-R.com and noticed that there are quite a few people dealing with nuisance algae problems. Now, there could be any number of factors contributing to each of these situations, but it did get me thinking about the ramifications of nutrient absorption in our tanks.

I would say that compared to larger systems, nanos are stocked quite a bit more densely, and there is the large possibility that more nutrients and waste products are introduced due to feedings, ratio of fish size to water volume, etc. I started thinking that the possibilities of an overload in nutrients could become a reality fairly early on in the life of a nano.

All of this started me thinking about maybe we nano-keepers will need to start seriously looking in the way we do things, setting up preventative and efficient methods of nutrient export before the trouble starts. Or, maybe this isn't even a problem? Due to sufficient and regular water changes, nutrients will never become a problem?

I am interested to hear all your thoughts on this.

 

[skylsdale]

I e-mailed Bomber over at RC about this and the possible ramifications of nutrient saturation in smaller systems compared to larger ones. Here is his reply:

I imagine Nano's would be the equivalent of the models that we use. Most are in the 10-20gal range and we add and subtract different things and time how long it takes them to crash. That's the jest of it.
Problem with water changes is nutrients build up between water changes. Those high nutrient periods can overwhelm sand and rock. Rocks are better able to handle it because they can shed it after a while and start over, sand just holds it.
Imagine that there's a constant low level of a nutrient that does not get past the animals or plants that can utilize it. When you increase that level, what's left over is stored in the rocks and sand. When the rocks and sand are full, you're fighting a higher level because the rocks and sand are not CYA. Unless there's some catastrophic event (power head stirs sand, something dies/crashes, Ph, salinity, temperature, etc all these things can trigger a nutrient release, especially in sand where extremely high levels can be stored.

You don't get readings because it's not floating around in the water, you will if you re-emulsify detritus. Such as convert phosphates to a form that you can test for. If not, it's organically bound and you can't test for it.

I have always been of the mind that skimmers were pretty much pointless in such a small system as a nano, assuming that a simple water change could remove more nutrients and organics than a skimmer. This may still be true, but I see now that the fluctuation can play a large part in this, and skimmers would help to keep nutrient levels at a consistently low level to prevent a minimal amount of organics from being soaked up by the sandbed and rock.

 

[Anonymous]

"Rocks are better able to handle it because they can shed it after a while and start over, sand just holds it."

I'd like to see some evidence behind that statement.

The small size of our tanks also makes it pretty affordable to just replace LR every couple of years as well. Spend $50 every two years for new live rock and don't use a DSB if you're really concerned about it.

 

[ufcd98]

please define depth in inches of DSB for this arguement

 

[skylsdale]

I would define a DSB around 5-6" of extremely fine particle sand (so no, I don't consider most nanos to have a DSB when people drop 3" into their tanks).

That aside, ANY sandbed can absorb nutrients and other things that can build up to be bad for our tanks. The whole philosophy behind a DSB is that it has a maximum capacity to do this, so nothing in the way of detritus removal needs to be done...for a while, anyway. That's the problem, people think the DSB is some "fix all" that enables them to not have to get all the crap out. You've got tons of critters in there, but you need to feed them. Eventually, there is a level of detritus and other things that don't get broken down. To put it simply, a DSB is a sponge that soaks this stuff up (and the LR as well). The problem is when the DSB hits terminal velocity and can't absorb any more. We're starting to see more and more people who have had their DSB's up for 4-5 years and their tanks are having insane hair and nuisance algae blooms. Many have noticed the hair algae actually started near the sandbed and moved its way up the rock, which makes sense since that is where nutrient would be exuding from.

I just started thinking about nanos and how this may affect them. I would rather not have to think of my systems in terms of annual remodeling. If I'm introducing fresh rock every year and doing the remodelling that goes along with, it's almost like a fresh system. My interest and concern is the long haul--not just for DSB's, but all the areas and ways nutrients can build up in our systems.

As was stated above, if fluctiations in nutrient levels are occuring, then we want to keep them consistently low--so skimmers would then have a very valid place in the world of nanos. With more and more people trying to keep predominantly SPS in their systems, hooking a Remora or Bakpak up to a 7-20 gal tank may become more of the norm, and we may actually see some pretty fantastic results.

 

[skylsdale]

I'd like to see some evidence behind that statement.

Here is the explanation I received:

Rock and sand release these things for different reasons. Bacterial turgor will cause rocks to release it on a more consistent basis, where as in sand bacteria has nothing to push against and you get more of a spreading out and filling up effect. If you have rocks on top of sand, the rocks will contribute greatly to the filling up of the sand.


And a link to the thread that explains the problem: http://reefcentral.com/forums/showthrea ... ost1941608

Here is my current train of thought on this: my issue is not JUST the DSB, but our tanks in general beause it's not just the DSB that absorbs nutrients--it's the rock, any sandbed at all, etc.

Although I think macro export is good, I am beginning to think that we should strive for our systems to be as consistent as possible and include as many export devices as possible. This is the best method for larger tanks, but because of the uniqueness and lack of some "nano-sized" equipment, we usually fall on macro export and water changes, which may still allow certain nutrient leves to climb and sit in the tank until a water change. As he stated:


quote:
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Imagine that there's a constant low level of a nutrient that does not get past the animals or plants that can utilize it. When you increase that level, what's left over is stored in the rocks and sand. When the rocks and sand are full, you're fighting a higher level because the rocks and sand are not CYA. Unless there's some catastrophic event (power head stirs sand, something dies/crashes, Ph, salinity, temperature, etc all these things can trigger a nutrient release, especially in sand where extremely high levels can be stored.
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Based on this, it sounds as if a water change may be too late if those nutrients have already been bound up in the rock and sand. Basically, this becomes a mainstay of the system, and any level introduced beyond that only serves to increase the levels that much more. That's why I'm starting to lean more toward the idea that skimming our tanks may not be too far "out there." Most would probably scoff at slapping a Bakpak or Remora on a 7-20 gal tank (probably more on the smaller end of the scale), but I think this could very well open up a whole new door of success. More and more people are keeping predominantly SPS nanos--running a skimmer (although it may seem overkill) would possibly help prevent these nutrients from ever really getting a foothold, providing a much cleaner environment for the corals. Granted, the reef is subject to upwellings of plankton from the depths where coral recieve good surges of food, but those upwellings are flushed out in a relatively short amount of time due to currents and wave action. While I don't know the specifics of what goes on, I would venture to say that very few nutrients every have a chance to establish themselves as any sort of hindering presence on the reef. Now imagine taking what appears to be an oversized skimmer on a relatively small tank--as you feed, the skimmer is going to be pulling that junk out as it remains uneaten. I know this is all basic stuff, but I think it's regarded as irrelavent in the nano community.

Then there's the argument that skimmers are taking out too much of the "good stuff" (plankton, etc.)...but large systems are pretty much devoid of that stuff; think how much more so our little 7, 10, 15, or 20 gal tanks are! I'm thinking it's an irrelavent argument for our small systems.

Just thinking out loud here.

 

[Anonymous]

sky,
I don't think you're crazy to suggest using a skimmer on a nano. Skimmers are an essential piece of equipment on large tanks, but it's not exactly something that can just be sized down and still be effective. I think tanks about 6 gallons and up or anything large enough to have a sump/refugium area are pretty much the lower limit for a skimmer that actually does anything useful.

I'm really intrigued by the possibility of running skimmerless systems. I don't think large tanks are "devoid" of zooplankton at all. Lots of crustacean and worm larvae are being produced and I'm guessing some of these are getting fed to corals on a fairly regular basis. I see no reason why this shouldn't occur in our smaller tanks as well, especially because of the increased amount of food offered. Do you get tubeworms on your glass? Like hundreds of them? Think about how many larvae must have been produced to have those few survive. The same goes for all the other animals in the tank. The amount of zooplankton pales in comparison to a wild reef, but it's there.

....just an aside--a friend of mine had a Montipora digitata colony triple in size from about a ping pong to baseball sized colony in an unlit refugium. The colony was stark white when he discovered it and had baseplated and everything. I see no explanation for this other than that it was receiving nutrition solely from plankton capture or absorbing nutrients from the water. Just food for thought....

Of course, there are unskimmed and skimmed tanks that both have SPS corals thriving. I think it comes down to personal methods rather than one "right way" to do it. I feel the same about DSBs. I don't plan on ever placing one in the same tank as SPS corals again (too much sedimentation), but they do have their merits. I have also heard or seen of many DSBs with lifespans far longer than 4-5 years (up to a decade and beyond). I just think it's far too easy to blame a tank crash on one thing. "My tank crashed, I have a DSB, therefore the DSB caused it" is something I've seen written many times, and I think it's the easy way out.

Whew!
I think you make my head hurt by thinking more than any other person on this board, sky , not to say I don't enjoy it. BTW, knowing how much you like biotope tanks, I think you'd really like my next tank. It's going to be a Hawaiian deep fore reef tank, with mostly species that are only found in Hawaii, and all of them occuring at depths below 65 feet. But since it's a 125 gallon tank, I will say no more in this forum

 

[skylsdale]

You bring up very good points as well, Matt. I learn best through debate and exchange of ideas, so this whole thing is pretty much my learning style (whereas some may see it as arguing or something of that nature).

Anyway, I've never run my tanks with a skimmer, and there is definitely merit to what you say. In all actuality, many of the species of corals we keep are highly adaptable in nature, being exposed to temps that would fry a captive system, occasionally being exposed to air, etc. I think we forget this sometimes...but also need to remember that they aren't quite as resiliant in captive settings given the same extreme conditions.

Your Hawaiian biotope is a nasty sabatoge of this thread...but a rabbit trail I always enjoy chasing. I've actually that about doing one of those. What is the proposed stocking plan. P. hawaiiensis? Potters angel? Lighting? Aquascape? Give me some details, man!

 

[Anonymous]

Well you asked for it:
Very low lighting (standard flourescent actinics), strong water flow that is unidirectional in nature (similar to the deep for reef), small amounts of live rock with lots of swimming space near the top, and a very thin layer of SD sand. Probably 8-10 Lysmata amboinensis to provide additional food, a 20 gallon refgium. Dead right on those fish, a pair of the anthias, a potter's, along with a pair of Cirrhilabrus jordani (which are also Hawaiian endemics IIRC), a harem of flasher wrasses, and a pair of Genicanthus angels (probably watanabei, they stay 5" or so and peaceful, only problem is the $400 price tag!). Should be pretty sick when it's all done.

 

[skylsdale]

Wow, sounds dead on to a lot of deep-water systems I've planned...but never had the resources to set up.

As a suggestion, that actinic lighting can get pretty hard on the eyes after a while, so you may want to try a white LED or two somewhere in the hood, and maybe direct them in at like a 45* angle. This will give make you feel a little "saner" when looking into the tank, and make it look like some tiny rays of sun are making it down.

Any plans for corals? I'm a little unfamiliar as to native corals around there, but a few colonies of Lobophyllia hemprichi left to grow absolutely HUGE would be cool. Plenty of sponges, tunicates, bivalves, etc. are expected.

Any specific reasoning behind going with a 125 gal for this?

 

[brandon4291]

All good points. What happens if one employs nutrient restriction in the aquarium design, limiting food input along with heavy waste production found in the usual fish load? Fish are still used, but reduced in number thereby reducing the single greatest source of required food input, detritus production, nitrogenous waste compounds and general environmental tax.

Is there a general concensus that it is possible to fully reduce detritus particles to inert substances given enough time and biodiversity, or does detritus seem to have limited reducibility--> stalling in decomposition as a continual waste nutrient source? These questions are the heart of the matter for me. Nice thread Skylsdale :!:

Brandon M.

 

[Anonymous]

Nice idea sky. Do LEDs make glitter lines like MH bulbs? Maybe I'll just go with an actinic and 10K bulb. I don't think the fish care too much about the color, as long as it's dim.

The 125 was practically a gift that fell into my lap. It's also just the right size for all the fish I want. I've wanted to keep a flasher/fairy/or anthias for as long as I can remember, but never had a big enough tank.

Sorry to hijack...

 

[skylsdale]

No problem. I don't think LED's make a glitter effect...but if you're doing deep-water you may not want it anyway. I would do an actinic bulb or two, and then between them mount something like a 24" 50/50 bulb. It's amazing how easily white bulbs will drown out the actinic. I think this would provide a pretty nice effect.

 

[skylsdale]

Back to the topic at hand, I would highly suggest folks checking this thread out: http://reefcentral.com/forums/showthrea ... did=263482

It addresses the issues that I think even we nanophytes need to look at in our advancemend of keeping small systems. In fact, we may be able to have an upper hand than those with larger systems, well, in regards to standard size equipment being used on our smaller systems.

Just something to think about.

 

[robitreef]

From reading what Skylsdale wrote, I was curious if cleaning out the sand bad is beneficial in the longer term. In my case I have my nano for almost six years and during that time I have lived in 4 different places, so I had to move my tank. Each time I siphoned out the accumulating sediment from the live sand. Hopefully I won't have to move it again as I am now a homeowner, and I would not intentionally break down my tank to alleviate nutrient removal. My sand layer is about 2-3" which does not qualify it as a DSB, but since any sand layer can be a nutrient trap, I wonder if this has extended the life of this "nutrient sink"? My initial assumption is no, but I (knock on wood) have not had any major algae problems with my tank. I did experience a 3-4 month period of red slime algae growing on patches of Live rock devoid of coralline algae, but now that has gone away by itself. I feed my three fish once a day in my 16 gal nano and the algae was probably a result of moving the tank. Again, just curious...

 

[skylsdale]

Of course this is pretty theoretical, but I would say that moving the tank and siphoning out parts of the sandbed have actually helped your tank. Did you add any sand back to replenish it, or simply put back what was left?

 

[robitreef]

When I emptied the tank, I tried to siphon out most of the particulate matter that was suspended in the remaining water in the tank, so I didn't lose a significant amount of sand. I never had a real intricate population of sand critters-mostly small tube worms and an occasional bristle worm. I have a serpent star that keeps things clean on the surface and some of my hermit crabs will eat detritus on the sand as well. I guess time will tell if I encounter any problems, but the tank recovered nicely after the move as well as the previous moves. My tank has an integrated skimmer which runs constantly. It is definately an advantage as well as a necessity IMO.

 

[skylsdale]

I have always thought that skimmers were overkill (e.g. unnecessary) for nanos...but I'm really starting to rethink that philosophy.

I'm curious what some think of the rate of trace elements in the water being taken out too quickly by "over rated" skimmers on nanos? I made a comment on another board that a skimmer rated for 100 gal tank being used on a 20 gal nano wouldn't be overkill, and someone mentioned that it would strip the water of these elements. I've never been a hard-core skimmer, so I'm infamiliar with this...and as far as I know there has really only been one "study" to find out what was in skimmate, so I'm not even sure if that person's statement stands on its own.

 

[robitreef]

Supposedly, Iodine is removed quickly as a result of skimming, but I don't know about other trace elements. Again, in my tank it came with a built in resovoir that came with the skimmer, so I have always used it and never found it to be deleterious.

 

[skylsdale]

I'm would like to weed out pure skeptical and theoretical information from the actual occurances within a tank. I may have to look into this a little more...