Keeping the impossible with a continuous phytoplankton and rotifers culture.

[sixty_reefer]

Hi folks, I’ve been debating for a while were to post this thread, in a way it’s a new tank although at the same time it’s more of a experiment, in the end I’ve decided to post here as all aspects are more experimental vs a tank build.

Keeping the impossible
It’s a technique that i have been developing for a while and would like to put it to practice, it basically consists of a purpose build system aimed at expanding the life of really hard to keep non photosynthetic corals ex. Dendronephthya and Acalycigorgia more commonly known as carnation coral and blueberry gorgonian.
I will aim at running the system for 6 months initially and then decide if I should expand the experiment or stop it depending on the experiment development.

The concept

My concept is simple, I’m planning on using a 15 gallon system with built in sump without live rock or sand in the display, the filtration will come from siporax media or similar that I will add to the rear chambers of the system, there won’t be any mechanical filtration.

The idea above is to be able to keep the rotifers available in the water column at all times, the sand and rock is usually good visually although I believe they will be detrimental for this exercise in the rear chambers I opted to use siporax for the same reason, the rotifer should be able to pass through the media without getting stuck.

Automated phytoplankton photo reactor and rotifer culture.

As a food source I will aim at using my continuously phytoplankton reactor that I’ve developed a few years back, this reactor will feed the rotifers culture only, there won’t be any phytoplankton dosed in the system as I am a strong believer that this corals are not vegetarians, the phytoplankton culture and rotifers will be automated with the aid of a dosing unit that will ensure that there is a fresh amount of rotifers available every 60 minutes. The culture will be matured before the experiment officially begins.

How to automate a phytoplankton culture

How to automate a phytoplankton culture In this article I will illustrate how to automate a phytoplankton culture, automation has been the key to successfully achieving stability in our hobby and with phytoplankton I feel that is no different...

www.reef2reef.com

Light source

There will be a very dim blue light a couple hours a day, as the corals won’t need it to survive and keep any algae issues at bay.

Additional targets

Some additional targets will be to try and identify if the corals are depleting any elements from the water column for this part of the research I I’m considering not doing any water changes to the system and have monthly icp testing made.
The results should indicate if some elements are being depleted from the system that could be essential to this corals care, I've got a feeling silica could be one of those limiting elements

In additional targets I also plan on observing the coral reaction to nitrogen dosing, in past experiments there was a reaction observed although there was many variables that didn’t allow me to expand on this particular path way.

Summary

In this treat I will use a small purpose build 15 gallon system without any fish, there will be one or two corals on the course of the experiment depending on local availability, the main source of nutrients will be coming from phytoplankton and nutrient that will be dosed to the system.

I’m still awaiting for some of the material to build the reactors and the system will still need to cycle and mature so bear with me as it may be some time before any coral is added to the system.

 

[Formulator]

I wish you luck! It sounds like you have thought through this quite a bit, so I hope I don’t throw a wrench in it, but a couple considerations in case you don’t already have a mitigation strategy…

Rotifers generate a surprising amount of ammonia. Keeping them in constant supply will be a significant bioload on the tank. This issue will be compounded by your lack of live rock and sand.

With continuous culturing and dosing of phyto, you will be dosing your tank with fertilizer. I actually was very close to imitating your continuous culture design a few months ago when I came across it on the forums, but I could not come up with a good way to stay in control of my trace elements when dosing an unknown amount of fertilizer. Maybe you don’t care or have the experience to tell you its a non-issue, but at least on paper it was a red flag to me. Not to mention the sensitive animals you plan to keep may be more sensitive to elevated levels of certain trace elements in the fertilizer.

 

[sixty_reefer]

I wish you luck! It sounds like you have thought through this quite a bit, so I hope I don’t throw a wrench in it, but a couple considerations in case you don’t already have a mitigation strategy…

Thank you, not everything there’s always something that can be easily overlooked and discussing the method usually helps point out possible mistakes in the experiment.
The chances of success are minimal although I’d like to try the idea with less variables that in the pass I thought that where important to remove from the equation.

Rotifers generate a surprising amount of ammonia. Keeping them in constant supply will be a significant bioload on the tank. This issue will be compounded by your lack of live rock and sand.

I wasn’t aware of this, I’ve never tested for ammonia in a culture before, hi have done the automated rotifer and not noticed any increase in it possibly due to being installed in a 60 gallon system.
I was considering adding ammonia using Randy’s ammonia thread to keep the bacteria going, something that I will have to look into once the initial run tests are made. In addition one of the aspects of the experiment was to add ammonia to the system as I’ve seen some responses from the coral in the past, if in fact there is a high amount of ammonia from the culture it could be beneficial to the overall experience.

With continuous culturing and dosing of phyto, you will be dosing your tank with fertilizer. I actually was very close to imitating your continuous culture design a few months ago when I came across it on the forums, but I could not come up with a good way to stay in control of my trace elements when dosing an unknown amount of fertilizer. Maybe you don’t care or have the experience to tell you it’s a non-issue, but at least on paper it was a red flag to me. Not to mention the sensitive animals you plan to keep may be more sensitive to elevated levels of certain trace elements in the fertilizer.

I don’t find the fertiliser a problem, I’m not sure if you had a chance to read the threads I’ve made in the past but my first step was to change the fertiliser, I now use TNC complete in the UK and there was another product that I’ve recommended for the US that have only inorganic P and N, in my opinion these fertilisers are more compatible with aquarium nutrients meaning that trace of fertiliser will be used by the aquarium biological load including microbes, coral and macro algaes.
In my opinion F2 was created to culture all types of phytoplankton including dinoflagellate meaning that the original formula may have silica that in some systems will not be used by the types of phytoplankton that we are trying to grow and cause problems if used.
In addition the N to P ratio is different in the new fertilisers respecting the 16 to 1 or close enough to Redfield ratio that phytoplankton requires, most f2 have a 1 to 1 or a 1 to 2 ratio meaning that at the end of the day there will be a excess p in the culture water.
The other aspect to the issue would be that anyone culturing phytoplankton the standard way would most likely be adding more P to their system using f2 that in a continuous way with a lower p concentration fertiliser.
In another tread I’ve made a few years back my system was P limited and I was having to dose it manually daily for many months.

This was the fertiliser I’ve recommended for the US as TNC only available in the UK the table shows the dilution of 1ml in a one litre solution of both products

 

[Formulator]

I’m not sure if you had a chance to read the threads I’ve made in the past but my first step was to change the fertiliser

Ahh, somehow I seem to have missed this important detail! I thought I had read through one of your threads but perhaps it was another design from another member because I don’t remember this being addressed. Thank you for your work on the subject! I may actually pursue this for my tank after all…

 

[sixty_reefer]

Ahh, somehow I seem to have missed this important detail! I thought I had read through one of your threads but perhaps it was another design from another member because I don’t remember this being addressed. Thank you for your work on the subject! I may actually pursue this for my tank after all…

My views on dosing phytoplankton have change slightly since, I’m finding that the main benefit was the increased zooplankton in the water column, with this new experiment I’m hoping I can isolate this aspect and hopefully identify that zooplankton would be more beneficial vs phytoplankton with less pollution to the system due to trapped phytoplankton in the sand bed and rocks.
In my 60g due to the amount doses of phytoplankton I was able to keep a good amount of zooplankton in suspense in the water column and corals reacted in a good way to the available food.
Below is a picture of my montipora Digitata that used to be fat due to the extra food available.

With this experiment I’m hoping to get some data on the effects of rotifers in hard to keep corals although in a near future I may add some normal corals also to see the difference.

 

[sixty_reefer]

Phase 1 completed

New tank cycled

Started with 100% old tank water from a friends reef.

Old Bag of media from the sump the same reef.

The bag was full of nice hitchhikers including a bristle worm that unfortunately is not needed for this exercise.

In the meantime I’m still waiting for parts ordered to build the phytoplankton photoreactor and the rotifers.

 

[sixty_reefer]

Nutrients starting point

No3 10 ppm
Po4 0.04 ppm
Kh 8

 

[SantaMonica]

Very nice. Love any type of automated bio system. Got close to doing this in 2008.

As for imbalances, you might try growing algae; it does luxury uptake of excess nutrients, up to a point, to help keep things corrected.

 

[sixty_reefer]

Most of the material needed arrived today, will need to re order the acrylic lids for the reactors as somehow I’ve messed up.