Approaches to feeding and nutrient export

Hello NPS forum,

While I don't currently have a dedicated NPS tank and I don't plan on having one in the near future, I'm trying to learn all I can about them because I appreciate the non-mainstream nature and the effort that's put into specific problems that probably could cross over to typical reef tanks with good success.

The main thing that seems to separate an NPS tank from a typical reef tank is the amount of food. I'm interested in learning more about the overall approaches people are using to feed their tanks and then export nutrients. Since I'm new to the NPS world I am sure this has all been debated at length so feel free to point me to old threads if that is the case.

It seems like there are basically two schools of thought. On the one hand, people are feeding extremely heavy amounts of prepared (dead) food. This creates a huge and instant nutrient load that seems to be typically handled by very powerful skimmers or other methods typical on a normal reef tank, just scaled up. Are there any NPS-specific approaches I am missing? I am surprised that methods like algae scrubbers are not more common, since they can target nutrients (which I would call "the real enemy") instead of directly removing the food items (as I suspect happens with skimmers or mechanical filtration, since it seems common to take these items offline during feedings).

The second school seems to be feeding live food, which doesn't seem to create the instant "hit" of nutrients that must be exported. I am surprised to see that this is not more common - most of the feeding threads on here seem to concentrate on things like dosers in minifridges, instead of, say, a plankton reactor to grow suitable live food. Is this because growing live food is just too difficult? Is the nutrient export load not really any different after all? Is there something else I'm missing?

Interested in hearing from anyone who has thoughts on these subjects.
 
I've read somewhere, that they had a bubble come on whenever they fed. The polyps of the NPS corals were able to grab the bubbles more easily than the food, but naturally the food stuck to the bubbles, and the corals were able to eat! They did this for Dendros (the harder ones.)
 
I've read somewhere, that they had a bubble come on whenever they fed. The polyps of the NPS corals were able to grab the bubbles more easily than the food, but naturally the food stuck to the bubbles, and the corals were able to eat! They did this for Dendros (the harder ones.)

i am really not sure what you're trying to say??

are you saying that someone had a device which would create bubbles in the tank, to which food would stick, which in return would be eaten by the nps corals???
 
The second school seems to be feeding live food, which doesn't seem to create the instant "hit" of nutrients that must be exported. I am surprised to see that this is not more common - most of the feeding threads on here seem to concentrate on things like dosers in minifridges, instead of, say, a plankton reactor to grow suitable live food. Is this because growing live food is just too difficult? Is the nutrient export load not really any different after all? Is there something else I'm missing?

Interested in hearing from anyone who has thoughts on these subjects.

The reason I think feeding live food is not so popular has a lot to do with the substantial extra effort involved in feeding live food. With the amount of food you have to feed NPS tank, it is no small effort growing and maintaining cultures of phyto, rotifers, copipods, etc. and feeding those on regular intervals. With all the other concerns and challenges of keeping an NPS tank, keeping up with live-food culture is another big headache. Furthermore, some live-food culture, namely phyto, is really inefficient and unnecessary at the hobbiest level.

Also, people like to emulate what has worked for others. Only a very select group sofar can really claim success with fully NPS tanks, particularly with the fussiest of NPS corals. From what I've seen, those select few have by and large used the first method you mentioned. From what I know, they all do it this way because of the shear density of food you need to have continuously in the water column. Doing this with live food would be very difficult.
 
Hello NPS forum,

While I don't currently have a dedicated NPS tank and I don't plan on having one in the near future, I'm trying to learn all I can about them because I appreciate the non-mainstream nature and the effort that's put into specific problems that probably could cross over to typical reef tanks with good success.

The main thing that seems to separate an NPS tank from a typical reef tank is the amount of food. I'm interested in learning more about the overall approaches people are using to feed their tanks and then export nutrients. Since I'm new to the NPS world I am sure this has all been debated at length so feel free to point me to old threads if that is the case.

It seems like there are basically two schools of thought. On the one hand, people are feeding extremely heavy amounts of prepared (dead) food. This creates a huge and instant nutrient load that seems to be typically handled by very powerful skimmers or other methods typical on a normal reef tank, just scaled up. Are there any NPS-specific approaches I am missing? I am surprised that methods like algae scrubbers are not more common, since they can target nutrients (which I would call "the real enemy") instead of directly removing the food items (as I suspect happens with skimmers or mechanical filtration, since it seems common to take these items offline during feedings).

The second school seems to be feeding live food, which doesn't seem to create the instant "hit" of nutrients that must be exported. I am surprised to see that this is not more common - most of the feeding threads on here seem to concentrate on things like dosers in minifridges, instead of, say, a plankton reactor to grow suitable live food. Is this because growing live food is just too difficult? Is the nutrient export load not really any different after all? Is there something else I'm missing?

Interested in hearing from anyone who has thoughts on these subjects.

Thank you for showing interest in ths niche of our hobby.

Should first start off with the breaking down of non-photosynthetic aquariums in general (sorry I hate using nps that term). Personally believe they should be broken down in to categories. Starting with the basic aquariums that containing, hardy non-photosynthetic, "LPS" corals going all the way up to complex filter feeding specific system. At each level they have a specific feeding requirement/ level of dedication. Starting to believe that eventually you need to choose sides, draw a line between keeping non- photosynthetic "LPS" and everything else.










Late here and will continue more tomorrow....

Mike
 
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Thanks for the info, Mike and aninja. That's what I'm looking for.

Is there any single high quality reference for general NPS care requirements or specifically matching food sizes/types to NPS corals, other than the "corals to stock" sticky ?

Mike, I am interested in hearing about the different types of NPS aquariums. I think I understand what you're getting at, in a very general sense. A tank full of sun corals will require different feeding technique than a tank full of carnation corals. Though (again) I am not specifically planning an NPS tank I think my interest lies somewhere in the middle - gorgs are the most attractive to me.
 
I think Steve Weast's approach to feeding his cold water tank is genius, we just need to replicate that but on a much larger scale for tropical species. Concentrate as much small particulate food as possible *correction: concentrate the appropriate amount of particulate food* in the tank in a given amount of time and then let the rest get filtered out, all with automation. If you can grow enough live food to create the proper food density in your tank on a regular basis, even better. IME, sun corals do great with this method of feeding as well and it practically eliminates the need to target feed them. Larger LPS like Rhizo's and large dendro's may still benefit from occasional target feeding of larger foods but can go for weeks without and still look very good. Most of the time I could never see with the naked eye what my corals were eating but they were definitely eating. In a tank full of gorgonians there may not even be much food left over to filter out after the first 30 minutes or so. That is another thing... these are suspension feeders, they filter particles out from your water. In other words, they are filters in themselves and convert food to energy, growth and reproduction. A densely populated NPS tank will do better than a sparsely populated one because no matter what you need a certain food density, but a sparsely populated tank has lots of extra uneaten food. Then you get pests like aiptasia!
 
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I have my NPS plumbed into my main SPS system but on a lower circulation rate...with the NPS tank housing a DSB with a Plenum. I have no Problems with high nutrient levels...it all gets eaten up :D
 
As far as benefits of live over frozen from a nutrition standpoint. I have been going back and forth with a public aquarium that has an nps tank and discussing different methodologies. They have constant cultures of phyto, rotifers, copepods of different species and artemia going all the time for their breeding program and various tanks. He said that he experimented with live/vs frozen and saw no real difference in the growth of the corals using live then when he used frozen. He does still use live phyto, but that is only because ironically, it is easier for him to use that as they culture gallons of the stuff constantly. But he has switched to frozen rotifers, copepods and the likes for ease of feeding and the tank is still doing quite well.
 
That's really interesting Uhuru. Are you basically saying that high instantaneous concentrations of food delivered intermittently in the water column is better than the same average concentration of food (ie. same total food) delivered at a constant rate? Why do you suppose this is? Does it have to do with the feeding responses of the corals?

That's a very important distinction to make: that bursts of food is better than a continuous trickle of the same amount of food.
 
I think one of the benefits is a large burst will better insure that all the polyps get food, especially in a densely stocked aquarium, where as a constant trickle has the potential to constantly feed the polyps that fall in the most direct path of the water flow and leaving the polyps out of the direct path with little amounts of food that end up being spread out.

I think that the best solution would be a slow trickle with occasional bursts of high concentrations.
 
That's really interesting Uhuru. Are you basically saying that high instantaneous concentrations of food delivered intermittently in the water column is better than the same average concentration of food (ie. same total food) delivered at a constant rate? Why do you suppose this is? Does it have to do with the feeding responses of the corals?

That's a very important distinction to make: that bursts of food is better than a continuous trickle of the same amount of food.

Definitely. It has to do with both feeding response and poor food capturing ability of many NPS corals including gorgonians, dendronephthya and scleronephthya. IME dendronephthya and scleronephthya are very poor food capturers with many small hungry polyps. Even though I fed my tank very well, the corals that were closest to the food output did noticeably better than the other corals in the tank. I never had luck with scleronephthya until I put a rock with some hitchhikers right next to the food output. Man did that make a difference. Even for the LPS keepers, if you like to have your tubastrea open most of the time, this method is also great for that. I never had to work hard to get them to open, just put them in the tank and within a couple of days at most they were open and feeding most of the time. This also works great for fish like anthias, angels and picky/shy eaters.
 
Agreed with the tubastrea comment. I had the most difficult time getting them to open until I moved them to a high flow portion of the tank. Now they're opened nearly 24/7.

I'll be building a house soon and want to have a full auxiliary tank room to cultivate live foods. I'd love to be able to just maintain cultures of rotifers, phyto and copepods and to automatically feed these to a display tank. I just don't have the room for all of that right now, so it is way easier to go the dead food route.
 
Yep, flow is very important too, both for feeding response and to help them capture the food.

When I first started I was always expecting to see polyps capturing food by closing all tentacles and engulfing the food particle. I think this is how a lot of people picture it. It is true that sometimes they capture food this way, but most of the time ALL of these corals capture food with 1 tentacle at a time. As food passes by they almost rhythmically bring each tentacle towards their mouth, depositing the food particles in their mouth. If you ever watch a sea apple feeding it is very much like that. Even sun corals feed that way. I've seen my rhizos catch oyster eggs that way too.
 
Yep, flow is very important too, both for feeding response and to help them capture the food.

When I first started I was always expecting to see polyps capturing food by closing all tentacles and engulfing the food particle. I think this is how a lot of people picture it. It is true that sometimes they capture food this way, but most of the time ALL of these corals capture food with 1 tentacle at a time. As food passes by they almost rhythmically bring each tentacle towards their mouth, depositing the food particles in their mouth. If you ever watch a sea apple feeding it is very much like that. Even sun corals feed that way. I've seen my rhizos catch oyster eggs that way too.

Here is a great video by morphologic on sun coral feeding on tiny zooplankton. This is how they eat most of the time.

<iframe src="http://player.vimeo.com/video/9437395?title=0&byline=0&portrait=0" width="400" height="225" frameborder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe><p><a href="http://vimeo.com/9437395">'The Sun Coral'</a> from <a href="http://vimeo.com/morphologic">MORPHOLOGIC</a> on <a href="http://vimeo.com">Vimeo</a>.</p>
 
Awesome, this is just the sort of discussion I was hoping to have in this thread.

uhuru, you talk about placement close to the "food output." You may have described this elsewhere, but what's the output of your feeding system like? I'm guessing a small diameter hose. Is it submerged or does it drip from above the water? Or, is it a venturi that's injecting food into a large/high flow closed loop or something?

In a larger tank would there be benefit from having multiple output locations? I'm picturing something like hiding a mess of airline tubes in the rockwork so you can squirt food right at certain corals. Of course with prepared/dead food I'd imagine you'd have to flush the line each time.
 
I believe his pumps put food directly into his return line through a "t" with a one way valve. Its somewhere up in the sticky for continuously feeding nps corals.
 
That's really interesting Uhuru. Are you basically saying that high instantaneous concentrations of food delivered intermittently in the water column is better than the same average concentration of food (ie. same total food) delivered at a constant rate? Why do you suppose this is? Does it have to do with the feeding responses of the corals?

That's a very important distinction to make: that bursts of food is better than a continuous trickle of the same amount of food.


I think the same as Uhuru (greetings), the intermittent feeding as dripping will have the benefit in relation to the apprehension.

in my case with the tanke with diverse gorgonias for example, after several years of experience they have confirmed it.

it is not the same to give the food in only one addition to the column of the water, where much of the food can stay in the substratum or can be exported by the skimmer or another filtrante.
 
Awesome, this is just the sort of discussion I was hoping to have in this thread.

uhuru, you talk about placement close to the "food output." You may have described this elsewhere, but what's the output of your feeding system like? I'm guessing a small diameter hose. Is it submerged or does it drip from above the water? Or, is it a venturi that's injecting food into a large/high flow closed loop or something?

In a larger tank would there be benefit from having multiple output locations? I'm picturing something like hiding a mess of airline tubes in the rockwork so you can squirt food right at certain corals. Of course with prepared/dead food I'd imagine you'd have to flush the line each time.

I had my food output teed into my return line as mentioned above. If I were to do it again I would have a separate pump and associated plumbing just for food. Even if you design it to flush the plumbing with clean water after each feeding, ideally make the plumbing as big as possible and use many unions for easy disassembly for cleaning.

Also, if I were to do it again I would have a chilled surge tank ABOVE the display and let gravity do the work. Fauna Marin designed a system like this for someone named Wolfgang Colsman do a google search for it.
 
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