took my fuge offline

I agree completely! and I let my fuge get to the point where the macro upkeep was out of hand, the DSB was being turned over but not efficiently enough.

It was too much upkeep for me right now so I took a step back and just let my mechanical filtration do the job for now. Nitrates have never been an issue for me anyways (could have been from the fuge though) so I will have to start monitoring them again to make sure they dont creep up on me. If need be, I can just take come of the macros from the fuge and grow them in a container in the sump under a light.

 

sweet. I like the idea of a fuge.... for pods of course... but also a big benefit is waste reduction. however, with the popularity of biopellets and the promise they bring, it will b tough to say how much use fuges will continue to be as a component to process waste. Media reactors are much simpler.

 

My feeling is a fuge is important because of common issues regarding nutrient imbalance, export and food shortage. A fuge can be a good method for keeping nutrients in check, and providing a source of food for the system. However, some recent changes in reefkeeping have reduced the necessity of such systems, and in some cases, there may now be more beneficial ways to maintain a diverse system under certain situations.

I think whether or not a fuge is needed for pod production depends on two main factors. First is how much food is there to sustain them and second how much predation there is in the system. If there is not enough food for the pod population to sustain large enough numbers, that they will persist in spite of predation, then a fuge can be helpful to provide shelter and keep the population going. It's been my experience that pod populations to come and go as food supply becomes limited and the balance shifts to predation.

Carbon dosing was a paradigm shift in reefkeeping IMO. Not just because it effectively reduced nutrients, but because it did so by diversifying the food web. This showed us that the food web may actually be carbon limited and increasing this nutrient source provided many benefits to our systems.

Besides reducing nutrients, people found that their corals coloration improved. There are essentially two possible reasons for this that I can think of at least. First, you are starving off the zooxanthellae and therefore the corals pigmentation is becoming more dominant as there is less brown zooxanthellae to influence the perceived coloration. However, in this scenario, then there is also less nutrients being provided to the coral and therefore it would seem reasonable to conclude that corals would have trouble maintaining their health in the long term and therefore producing this colorful pigmentation. The second scenario is corals are deriving more food from the environment and therefore, less nutrients are required from the zoox and the coral can reduce it's dependence on it's symbionts some also shifting the color balance to the corals natural pigmentation. However, I believe this does so in a more sustainable manner.

This does not necessarily address pods however. Pods are another component of the food web, but rely largely on algae and diatoms. In my own system, I have started dosing silicates in order to promote the pod population. I have found the result to be a sustained, system-wide, explosion of pods.

I think a DSB is a good way to maintain denitrification and diversify infauna. However, too much reliance on a DSB can become problematic, as it can be a nutrient sink and therefore introduce some potential problems as well. My tanks sand is not a DSB, it averages 2" over the main display and about 1.5" in the second display. However, there are areas where it is deeper, getting up to about 3" in parts, in the main display for example. This does seem to be sufficient to maintain diverse infauna, but IMO, by limiting the dependence on any one component of the system, such as this, there is an increased overall stability in the system as a whole. For example carbon and silica dosing adds to the infauna and denitrification. However, I can make adjustments more quickly to fine tune the system as needed.

I agree. A fuge is beneficial in many systems, but cookie cutter systems have limitations. Especially as we push the limits in our reef tanks, there are always going to be circumstances where deviation from the norm may provide great benefit.

Edit: also, just to clarify, I am not saying having a DSB or a fuge etc.. make a system a "cookie cutter" system. I reserve the term for circumstances where this is done out of belief that a system should have these; without considering the full rationale behind it. Even if this is the case, that is not necessarily a negative, as less experience reefers or reefers less inclined deviate from what is tried and tested, may benefit from such systems as the ground work for a successful system has already been laid out to follow. However, just the same, not all systems necessarily need to follow the mold and some may benefit from deviation.

 

I found with my fuge it did not work well other then holding my cheto and letting it grow outside the DT. But I now swear by it - I found that after it had matured it started working 100% - it not only helps with PH and Pods but it also gives me an early sign of any possible issues.
I find it also helps remove waste and allows extra oxygen to be in the tank at night.

Great info BTW m2434

 

That's actually a pretty good point. The vast majority of oxygen in water is from photosynthisis. Head and shoulders over any mechanical means we have. Even natural reefs are shown to become hypoxic at night.

While bio pellets are good at reducing N and P, perhaps time will still show macro algae to be the best at doing that and keeping our tanks oxygenated at night. I'm sure it does not compare to daylight out puts and micro algae... but everything helps in our generally over stocked tanks.

 

Any one can have a glass box with a fish and do water changes. Nature itself is much much more diverse and no matter how hard we try we can never replicate it in a glass box. Just so many interactions and food chains it boggles the mind.

However, what intrigues me about this hobby is just how much we can incorporate and how diverse we can make our system. What really has been interesting me lately... not having a stunning glass box filled with starved out colored up SPS.... but to have that in addition to a thriving Fuge and a benthic tank. I may be tankless now... heck even for some time to come.... but I keep envisioning a MH lit 6500k (or maybe even natural light) fuge with all kinds of macro algaes and critters along with a huge unlit tub of live rock all driving a minimalist SPS tank with LOTS of small reef fish. Heck maybe 3 connected tanks of grass lands (fuge) at 6500-10K, LPS at 14K and SPS at 20K. That would be pretty darn cool I think.

 

Yes! So true.

You know, when the zeovit system, vodka dosing and other carbon dosing schemes started gaining popularity. Many people argued that they were making the corals more colorful by starving out the zoox. This was one hypothesis, however, IMO this has been show to be incorrect. If this was the case, there is no way you would not have sustained coloration and growth. Now that people have had such systems running for a number of years, with sustained coloration and growth this appears to be incorrect.

It is well documented that, to a large extent, corals can regulate density of their symbionts to meet their nutritional needs. Lighting for example does this, if you increase the light, you will tend to decrease the zoox density, as they are now able to provide sufficient nutrients at lower densities.

It has been hypothosized that increased feeding will have the same effect. This appears to be the case IMO. My interpretation anyways, is that carbon dosing appears to increase bacterioplankton, which in turn provides a food source for our corals and results in lower densities of zooxanthellae and therefore more prominent pigmentation. I believe that the benefit to this over relaying solely on zoox, is that the zooxanthellae biproducts may be harmful to some extent. Reducing reliance on zoox, will likely reduce these biproducts and may therefore help improve long-term health outcomes.

Absolutely, this is a great goal. One problem though is macro does not go well with SPS systems. They have too low nutrient levels. IME, adding a carbon source, and in my case a silicate source, will absolutely increase the density of benthic organisms though. However, it will do so at a cost, that being nutrients available to the macro algae will be reduced, in many cases to the point it they become too limited to sustain macro algae.

Of course, it's possible that if I added and potasium nitrate for example, to my dosing scheme, maybe with carbon dosing, silicate dosing would help increase the benthic organisms and the potasium nitrate would help maintain the macro algae. Of course this still dosn't consider phosphate, which would be required to some extent for macro algae. I could remove some GFO though for example. However, phosphate and nitrates have both repeatedly been shown to decrease the growth rate of scleractinians.

That leads to what I see as a significant benifit of nutrient reduction via carbon dosing and bacteria, over the use of macro algae. As mentioned, carbon dosing for nutrient reduction appears to mainly work by enhancing bacterial growth. Heterotrophic bacteria can feed on decaying organics. Therefore, in all likelihood, the bacteria will consume the decaying organic material before it decays into soluble inorganic forms which can inhibit coral growth. Macro algae can't. It may consume the soluble forms, immediately as they become available for example, however, they still need to enter the water column as inorganic nutrients, where they may also effect coral growth. This is sort of the catch 22 for a diverse system. Making a system more diverse can make many things more difficult. It's a personal preference which areas you want to focus on.



Going back to the fuge though, it is termed a "refugium", because it provides refuge for various critters. If these critters can survie in a display
this function is not necessary. As mentioned previously, this can occur if the population growth is faster than, or equal to, the rate of predation. A fuge can have benefits, but can also lead to problems, again it's a personal preference whether or not the benefits outweigh the potential issues and this will also depend on the particular system.

Also, as too Oxygen, certainly this is valid, however, as shown By Eric Borneman here:The Need to Breathe, Part 3: Real Tanks and Real Importance by Eric Borneman - Reefkeeping.com
a protein skimmer also provides a lot of O2 for example. Other sources of O2 in my tank are lots of open surface area, with significant aggitaion and I have a basement sump, so, the water flowing down 10'+ of PVC is being mixed with a significant amount of O2 the whole way. Also, althouhg there is no macro algae, my 2nd display is still on a quasi-reverse photo period from the main display. In total the combined photoperiod of both displays covers about 19 hours, but 12 hours each.

Also, while in Eric's examples, photosynthesis provided a lot O2, this is limited by the availible nutrients. In a ULNS, it is likely macro algae will not provide the same effect, if you can get it to grow to begin with. Again though, it depends on your goals, as to if this is a worthwhile compromise.

 

I have found a sandbed will easily turn into a septic tank, if it doesn't have proper care. I avoid them now.

 

Hard to have it all. Ya... and when I say starved out... that is only meant that SPS is not relying on zoox and it's needs are being met with plenty of light and other sources.

In reading Erics articles his point was that the majority of O2 comes from photosythisis. We can't match it. But that yes skimmers do provide a fair amount and other mixing such as overflows. We know open tops are good for exchange, but they actually don't do much. And he used power heads and surface agitation and found very little impact. Good point though about ULNS though.

If my goal was to have it all... I've wondered if reduced skimming would keep waste levels up enough to support algae. But the macro tank would have to be fed a fair amount.... yet be able to polish the nutrients off before exiting. I've thought of multi pass stuff..... baffling a tank into a long pass with slow flow and see how much algae is growing at the end.... enough so that the nutrients were stripped to go to the LPS/SPS sytem. Even if this could not be accomplished with a nice display tank... I bet it could be with a algae turf scrubber type setup with just GHA growing and cleaning things up. A ATS is a bit complicated... but a lot of the same stuff could be accomplished with a well lit shallow long pass type filter.... sans skimming perhaps for a more natural setup.

Who knows... only provide enough flow to the "filter" to run a long pass ATS into a bentic tank with LR and send it back to the display tanks.

OK.... we are WAY off topic now but still interesting to me. Sorry Dingo.

 

Whoops :-/

Well, I'm still trying to visualize some parts of your plan, but sounds very cool. Definitely ambitious, but sounds like fun