Coral Feeding - what does the latest science say?

[tenurepro]

Hi All,
Here is a video i just released discussing two papers that study the effect of different coral foods on coral growth and health. The emphasis is on stony corals.



One paper is a bit old and i know a few of you know about it. The other was published late last year, which calls into question some of the findings of the older paper.
paper 1:
https://www.cambridge.org/core/jour...ficial-foods/BC8845A6BF25F08A37D398A0137C4AEF
paper 2:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0207956

Together, the two papers review the following foods Reef-Roids, Reef Chili, Roti-Feast, Oyster Eggs, Marine Snow, Microvert, Plankton Diet, Phytoplan, Salifert Coral food, in addition to one type of live food along with raw sea water.

Big picture summary, while a small proportion of the commercial diets did boost coral growth above the controls (=controls being heavily filtered sea water), the commercial diets didn't come close to raw unfiltered sea water (for Acropora) and live brime shrimp for Pocillopora. There is a discussion in the video about what is in raw seawater that makes acropora grow like crazy, and the value of promoting the diversity of microorganisms in our tanks.

This is likely going to be a controversial topic, so please keep an open mind when you watch the video.

Cheers and happy reefing!

 

[NY_Caveman]

This was excellent. Thanks @tenurepro

 

[tenurepro]

This was excellent. Thanks @tenurepro

Thanks!

 

[madweazl]

Havent had a chance to watch the video yet but the article was great, thanks for the link. Sure wish I still had access to the Scripp's water

 

[tenurepro]

Havent had a chance to watch the video yet but the article was great, thanks for the link. Sure wish I still had access to the Scripp's water

Glad you liked it

 

[whytey963]

Awesome Video Thanks

 

[sde1500]

Interesting listen. I'd argue that ultra filtered sea water is a great control, as that is what most of us use in our tanks. I've been reading a lot recently on coral nutrition and feeding, can go down quite the rabbit hole. Dana Riddle did a pretty good series in Advanced Aquarist too. I'll have to read this new paper. Curious how we could better encourage life in the tank. Obviously introducing things like copepods, amphipods, snails and other small creatures help. I'd doubt that bottled bacteria has a lasting effect, but would carbon dosing to increase bacterial populations help? Personally did some culturing for a bit up until last year, looking to get back into it. I'd like to do 1 or 2 rotifer varieties, brine shrimp, and 2-3 pods, along with 2 phyto varieties to feed them and the tank. I feel that would provide a good variety of micro life for the tank and hope that I could see some good results from it.

 

[jtl]

Following.

 

[tenurepro]

Interesting listen. I'd argue that ultra filtered sea water is a great control, as that is what most of us use in our tanks. I've been reading a lot recently on coral nutrition and feeding, can go down quite the rabbit hole. Dana Riddle did a pretty good series in Advanced Aquarist too. I'll have to read this new paper. Curious how we could better encourage life in the tank. Obviously introducing things like copepods, amphipods, snails and other small creatures help. I'd doubt that bottled bacteria has a lasting effect, but would carbon dosing to increase bacterial populations help? Personally did some culturing for a bit up until last year, looking to get back into it. I'd like to do 1 or 2 rotifer varieties, brine shrimp, and 2-3 pods, along with 2 phyto varieties to feed them and the tank. I feel that would provide a good variety of micro life for the tank and hope that I could see some good results from it.

Interesting thoughts. Thanks for sharing.
I would think that carbon dosing would have a negative effect on tank biodiversity as it would favor the bacteria that strive under carbon dosing at the expense of other critters and micro algae. I would think that having a large system volume with a decent fuge will help increase diversity. Starting everything with dry rock is not likely great. What we need is a way to seed the tank with beneficial organisms without introducing unwanted pests.

 

[Mortie31]

Thankyou for this... yet again suspicion and doubts raised over several of the very common products we regularly buy, its interesting that natural, and live food is better in this paper, and potentially how important the bacteria/ virus levels in the unfiltered NSW. I think this summary page is spot on. @Lasse @Paul B @Thales @MnFish1 I’d be interested in your opinions on the video.

 

[jtl]

I have often wondered if I keep my tank too clean and strip the water of valuable nutrients. I was getting some GHA so I cut back on feeding and reduced my NO3 and PO4 which are currently 1.5 and .018, respectively. I am also perhaps over concerned about the appearance of my sump and particularly my refugium which is nothing more than a box of water since my chaeto doesn't grow. I think I may change my methods, remove the filter media except on tank cleaning days and let the refugium collect detritus (my DT flows to the refugium than to the skimmer and finally to the return section).

I also think that Paul's theory of feeding clams has merit. I recently purchased 2 pounds of mussels and mixed them with a hand blender. I ended up with quite a bit of "food" so I froze most of it. What I didn't freeze I have been added to the tank. It is a little void of pieces for the fish of which I only have 4 small ones but the slurry circulates around all of the corals. Time will tell if it promotes the growth of algae.

 

[sde1500]

Interesting thoughts. Thanks for sharing.
I would think that carbon dosing would have a negative effect on tank biodiversity as it would favor the bacteria that strive under carbon dosing at the expense of other critters and micro algae.

Would it though? As long as the dosing isn't causing huge blooms, but is allowing for more bacteria to be present and consuming not just the added carbon but existing nitrates and phosphates, I would imagine you are artificially increasing the population of an organism that wasn't abundant before and consuming existing resources that previously weren't. I believe I remember reading, or hearing maybe in that BRS video on feeding coral, that nitrates and phosphates are consumed at higher levels in the home aquariums due to lack of other resources available to them such as micro fauna. In our captive tanks, unless we can add water straight from the ocean, its foods we have to cultivate, likely including some in separate tanks. Doing so would lessen the corals need for N/P and allow more for consumption by bacteria that could possibly be a food source for corals as well.

 

[Mortie31]

Would it though? As long as the dosing isn't causing huge blooms, but is allowing for more bacteria to be present and consuming not just the added carbon but existing nitrates and phosphates, I would imagine you are artificially increasing the population of an organism that wasn't abundant before and consuming existing resources that previously weren't. I believe I remember reading, or hearing maybe in that BRS video on feeding coral, that nitrates and phosphates are consumed at higher levels in the home aquariums due to lack of other resources available to them such as micro fauna. In our captive tanks, unless we can add water straight from the ocean, its foods we have to cultivate, likely including some in separate tanks. Doing so would lessen the corals need for N/P and allow more for consumption by bacteria that could possibly be a food source for corals as well.

Not sure about the increased bacteria, but if you look at the higher level in the unfiltered water, it would appear to be beneficial, but don’t know about the strain differences and there not discussed.. I agree cultivating live food (phyto, rotis etc) maybe the way forward, as even the best/ most expensive coral food in this experiment did nothing...

 

[hart24601]

I am also of the mind that carbon dosing would boost micro fauna. I carbon dose just for that reason. It feeds the bacteria, but in turn all the larger micro fauna that feeds off bacteria then have a food supply. I have carbon dosed for years just to feed the food web. One generally notices a great increase in filter feeders like tube worms and sponges with carbon dosing.

 

[jtl]

Were they simply adding some unfiltered seawater for the biodiversity or was the entire tank sea water? I only live 3 blocks from the Gulf but hauling several gallons of water in across the beach and loading it into my car is not something I would care to do. Also the only way I would use the natural water is if I could collect it far from shore due to pollutants.

 

[jtl]

Does carbon dosing cause other problems like GHA or Cyano?

 

[sde1500]

Does carbon dosing cause other problems like GHA or Cyano?

It should counter GHA because it promotes bacterial growth to consume the added carbon along with N/P. I believe some aggressive vodka dosing can lead to cyano.

 

[itsforte]

How come the result with raw and ctl (unfed) growing faster than feeding ? This is non sense.
With this result, why do we need to feed? keeping tons of seawater is easier and cheaper than coral food.
It means, in the experiment, they are not good coral keeper. The max growing rate is 10- 15 % from 6cm in 90 days, equals to 0.6-0.9 cm growing in 90days. It's quit few. As we know, for mille, it grows faster than this.
BTW, there is no picture to prove the final result compared with origin size.
Or we have to doubt how much they've sponsored by AIMS ?

 

[tenurepro]

Were they simply adding some unfiltered seawater for the biodiversity or was the entire tank sea water? I only live 3 blocks from the Gulf but hauling several gallons of water in across the beach and loading it into my car is not something I would care to do. Also the only way I would use the natural water is if I could collect it far from shore due to pollutants.

Let me check

 

[tenurepro]

Were they simply adding some unfiltered seawater for the biodiversity or was the entire tank sea water? I only live 3 blocks from the Gulf but hauling several gallons of water in across the beach and loading it into my car is not something I would care to do. Also the only way I would use the natural water is if I could collect it far from shore due to pollutants.

The authors say and I quote “Nubbins were maintained in ultra-filtered seawater (0.04 μm) (unfiltered in the RAW treatments) with a flow-through rate of 0.8L min-1 (1 turn-over h-1) and a circulation pump to assist with water flow (flow rate 25L min-1)”
So the ‘raw’ seawater treatment consisted of a tank full of natural unfiltered sea water.
There isn’t a lot of info on how often this was changed... I’ll email the author.

Yeah pollution is an issue