Algae Growth. Dead v Live Rock

[Dan_P]

This is just an interesting demonstration.

I placed 200 mL aquarium water in each of two identical plastic 0.25 L containers. In one container I placed a piece of clean aragonite rubble and in the other a piece of aragonite rubble that has been in my aquarium some months. The containers were illuminated 12 hours a day and aerated. After three days, the aquarium water was replaced with Instant Ocean with nitrate and phosphate at the same concentrations as the aquarium water. This medium was replaced every three days. After one week here are the results. Enjoy!

 

[Timfish]

I don't understand the point of your thread? I think it's obvious the rock that already had algae on it would grow algae considerably faster than the rock that didn't have algae on it. Sorry, but I think Aquabiomics article is a better demonstration of what happens with different types of live rock.

Establishing a Healthy Microbiome in a New Aquarium Using Live Rock

Studying the effects of live rock in a newly established aquarium shows that high-quality live rock promotes the rapid establishment of an effective biological filter and a microbial community similar to those found in mature reef tanks.

www.reef2reef.com

 

[Dan_P]

I don't understand the point of your thread? I think it's obvious the rock that already had algae on it would grow algae considerably faster than the rock that didn't have algae on it. Sorry, but I think Aquabiomics article is a better demonstration of what happens with different types of live rock.

Establishing a Healthy Microbiome in a New Aquarium Using Live Rock

Studying the effects of live rock in a newly established aquarium shows that high-quality live rock promotes the rapid establishment of an effective biological filter and a microbial community similar to those found in mature reef tanks.

www.reef2reef.com

One question I have is why does the live rock ”inhibit” the green algae from growing all over the container? My second question that I will try to answer is whether the biofilm that is scraped from the surfaces of the container with the live rock “inhibit” the growth of algae in a clean container. Can I just keep transferring the biofilm forever to clean containers and never have algae growth?

Yes, Aquabiomics experiment was enlightening and I was gratified to have reproduced some of the results with a simpler experimental design. Maybe I should have the organisms in the inhibiting biofilm analyzed or maybe just sell the stuff

 

[Randy Holmes-Farley Verified Community Expert]

You think it's an inhibition effect as opposed to "it just took up more nutrients, leaving less (of something, maybe not measured, like iron) in the water for surface algae to use" effect

 

[Dan_P]

You think it's an inhibition effect as opposed to "it just took up more nutrients, leaving less (of something, maybe not measured, like iron) in the water for surface algae to use" effect

Yes, the live rock could be starving the surface growth. Aquarium sand has has a similar effect as live rock. If I remove the live rock, surface growth is still inhibited, but the inhibition seems to be waning (An argument for starvation). If I continually expose the surface with aquarium water in the presence of live rock, the live rock is colonized with algae but the surfaces are still clean (Anti-starvation argument maybe).

It seems like there might be several candidate causes: live rock starves surface growth (K.I.S.S), live rock is providing bacteria colonists that interfere with surface settlement or growth, live rock “metabolism” is feeding (carbon dosing) the bacteria biofilm which in turn is interfering with surface growth.

I am contemplating removing the biofilm from the “clean” surface and see if it alone can “inhibit” algae growth on a sterile surface. Most of the treatment cultures will just grow for a month or maybe until they grow cyanobacteria. The next round of experiments will try to erase the live rock effect with a high contraction of nutrients and trace elements like the f/2 medium.

Funny thing about this effort is that it started out just trying to culture different species of algae.

 

[Timfish]

Sorry! I missed the differences in algae growing on the surfaces of the container . Along with sponges, biofilms in reefs systems certainly need closer attention as they have been shown to drasticely alter the sorbtion properties of the substrates they grow on, and can sequester significant amounts of nutrients as well as metals and other compounds they are certainly players in aquaria. I've seen thin white lines form in algae growing on glass that slowly move across the surface removing the algae and leaving clear areas behind, I'll dig up photos for you. Now that we can test for microbial stuff it would be interesting to see if we can demonstrate a succession of microbes and algae.

 

[sixty_reefer]

This is just an interesting demonstration.

I placed 200 mL aquarium water in each of two identical plastic 0.25 L containers. In one container I placed a piece of clean aragonite rubble and in the other a piece of aragonite rubble that has been in my aquarium some months. The containers were illuminated 12 hours a day and aerated. After three days, the aquarium water was replaced with Instant Ocean with nitrate and phosphate at the same concentrations as the aquarium water. This medium was replaced every three days. After one week here are the results. Enjoy!

Interesting work Dan, Did you replace the water every 3 days with new water and added phosphates and nitrates?
Did you measure the consumption in between water changes also?

 

[njreefkeeper]

You think it's an inhibition effect as opposed to "it just took up more nutrients, leaving less (of something, maybe not measured, like iron) in the water for surface algae to use" effect

^^^me thinks this

 

[Dan_P]

Interesting work Dan, Did you replace the water every 3 days with new water and added phosphates and nitrates?
Did you measure the consumption in between water changes also?

Regular water changes with nutrients added.

Unfortunately, my schedule at this time only permits visual inspection and I will need to repeat this work. I snuck this in because I just wanted to see if I could culture different species of algae.

 

[Dan_P]

^^^me thinks this

Me too, but will confirm with follow up work.

I did a quick peek at the brownish material seen in the live rock treatment. Dominated by closely pack circular cells about a fifth the size of the Amphidinium dinoflagellate that is also present. Cyanobacteria hormogonia also detected. This is starting to sound like a demonstration of “I starved my system and dinoflagellates bloomed”

More info coming…

 

[ISpeakForTheSeas]

Having been doing some intensive study on biofilms lately, some bacteria species actually do inhibit the growth of other species/microorganisms, but these don't necessarily inhibit all potential colonizers. So, even if your biofilm there prevents the spread of some algae/biofilm, it likely won't inhibit all or even most colonizers from taking root. In other words, it's possible that it actually did - accounting for nutrient uptake of the colonizing algae - inhibit the spread in this case, but there's no guarantee it would do so in other cases.

Additionally, different species of bacteria and other colonizing microorganisms prefer/require different substrates to colonize (i.e. you'll find species "x" on substrate "y" but not on substrate "z"), so it's also possible that you just had different species of microorganisms on the rocks. It also seems possible to me that - even if you had the same species in both tanks/on both rocks - one species just happened to grow faster in one tank and another grew faster in the other.

That said, I agree that the simplest (and most likely explanation) is that the nutrient uptake discussed above.

Sorry! I missed the differences in algae growing on the surfaces of the container . Along with sponges, biofilms in reefs systems certainly need closer attention as they have been shown to drasticely alter the sorbtion properties of the substrates they grow on, and can sequester significant amounts of nutrients as well as metals and other compounds they are certainly players in aquaria. I've seen thin white lines form in algae growing on glass that slowly move across the surface removing the algae and leaving clear areas behind, I'll dig up photos for you. Now that we can test for microbial stuff it would be interesting to see if we can demonstrate a succession of microbes and algae.

I know a couple of studies showing the succession of bacterial microbes in biofilms, but I'm not sure if any studies have been done showing the successional interaction between biofilms (or other microbes) and established algae. It would be interesting research.

 

[Dan_P]

Having been doing some intensive study on biofilms lately, some bacteria species actually do inhibit the growth of other species/microorganisms, but these don't necessarily inhibit all potential colonizers. So, even if your biofilm there prevents the spread of some algae/biofilm, it likely won't inhibit all or even most colonizers from taking root. In other words, it's possible that it actually did - accounting for nutrient uptake of the colonizing algae - inhibit the spread in this case, but there's no guarantee it would do so in other cases.

Additionally, different species of bacteria and other colonizing microorganisms prefer/require different substrates to colonize (i.e. you'll find species "x" on substrate "y" but not on substrate "z"), so it's also possible that you just had different species of microorganisms on the rocks. It also seems possible to me that - even if you had the same species in both tanks/on both rocks - one species just happened to grow faster in one tank and another grew faster in the other.

That said, I agree that the simplest (and most likely explanation) is that the nutrient uptake discussed above.

I know a couple of studies showing the succession of bacterial microbes in biofilms, but I'm not sure if any studies have been done showing the successional interaction between biofilms (or other microbes) and established algae. It would be interesting research.

Interesting and useful ideas here, especially the one on substrate preference.

 

[Dan_P]

Sorry! I missed the differences in algae growing on the surfaces of the container . Along with sponges, biofilms in reefs systems certainly need closer attention as they have been shown to drasticely alter the sorbtion properties of the substrates they grow on, and can sequester significant amounts of nutrients as well as metals and other compounds they are certainly players in aquaria. I've seen thin white lines form in algae growing on glass that slowly move across the surface removing the algae and leaving clear areas behind, I'll dig up photos for you. Now that we can test for microbial stuff it would be interesting to see if we can demonstrate a succession of microbes and algae.

Thanks!

 

[Timfish]

Thanks!

Here's the pics of a white band seperateing algae from clear areas. One is from a system dismanteld 7 years ago and only had damsels at the time of the pic and has several small areas left middle. The other two are a wide and narrower shots of the same area from a tank that was lost in the 2021 freeze except for a couple small bubble corals and xenia and has been fishless since then with just a handful of small water changes.

#1


#2 & #3

 

[Dan_P]

Here's the pics of a white band seperateing algae from clear areas. One is from a system dismanteld 7 years ago and only had damsels at the time of the pic and has several small areas left middle. The other two are a wide and narrower shots of the same area from a tank that was lost in the 2021 freeze except for a couple small bubble corals and xenia and has been fishless since then with just a handful of small water changes.

#1


#2 & #3

I see the areas. I am wondering whether these area might also include blanched algae left over from a virus or fungus infection? I have seen clear circular areas in cyanobacteria films and wondered if there was an analogy here.

 

[fish farmer]

Here's the pics of a white band seperateing algae from clear areas. One is from a system dismanteld 7 years ago and only had damsels at the time of the pic and has several small areas left middle. The other two are a wide and narrower shots of the same area from a tank that was lost in the 2021 freeze except for a couple small bubble corals and xenia and has been fishless since then with just a handful of small water changes.

#1


#2 & #3

Those white pinkish areas in #2 and 3 look like coralline algae to me.

 

[Garf]

I see the areas. I am wondering whether these area might also include blanched algae left over from a virus or fungus infection? I have seen clear circular areas in cyanobacteria films and wondered if there was an analogy here.

I did an experiment by leaving an established turf scrubber screen unmolested in an established tank, if that helps;

 

[Dan_P]

I did an experiment by leaving an established turf scrubber screen unmolested in an established tank, if that helps;

Lot going on here! Can you provide some more detail?