Increased flow caused algae growth on Montipora

Tripod1404 · 03/23/2018, 02:31 PM

Hello guy,

Couple of week ago I increased the flow in my SPS tank and rearranged the power heads. I did this mainly because I was not satisfied with the growth patterns of several montipora even tough they were growing and healthy. Digitatas were growing nicely but they were producing very this branches. Here I mean like very very thin branches, I had several cases where fish bumped into and broke them (it was a good natural fraging, now I have 3 colonies

). On top of that, they seemed to be more intrested in encrusting than producing branches. Other encrusting&spiking montis like spongedas and setosas were mainly encrusting and were only producing very short spikes. I interpreted all these as sings of low flow, since SPS corals generally behave this way when flow is low.

Anyway, after I increased the flow, several weeks later I observed algae growing on top of some montis. I would not say the flow is direct, it is generated by two wave pumps and one gyre pump, so there is very little to non laminar flow and it is extremely random. Total turnover rate is close to 100X.

One digitata has small patch of algae growing on a "stopped growth tip", as well as on the side of one of the branches. But aside from this the coral looks healthy. It has full polyp extension.and even the sites that have algae on them still have their polyps. During the day it is hard to see the algae as open polyps cover them. But at night and early morning, before polyps open, I can see patches of brown algae. There doesn't seem to be noticeable tissue recession, but the fact that algae can take a hold on make me believe there probably is.

In addition to this, one spongeda has tissue recession at certain regions which get brown algae on them. It is not widespread, there are just few small spots, mainly "old regions" that are shaded by the spikes. Here by old I mean parts of the coral that are found towards the center. Younger, newly encrusted regions and spikes dont seem to get algae.

Paradoxically, a nearby purple stylophora, an acro that gets brutal amounts of flow and certain other digitatas around seem to be okay.

So this makes me question if it is a flow issue, or simply coral "gave up" on certain regions with the change in the flow. You know as coral colony grow, regions that get no light, or no flow eventually die out, even though the colony is healthy.

In your opinion, should I change the flow or reduce it, or should I ignore the algae and wait for the those corals to acclimate to it? Like I said before, aside from the several patches of algae, the colonies doesn't look stressed or unhappy and are actually growing at other sides.

As of right now the only this I do is to try to blow away the patches of algae with a pipette. But since they already grow on a coral that gets good amount of flow, it is very hard to blow then and I am wondering if trying to blow them away causes more tissue recession.

03/23/2018, 02:31 PM	#1
Tripod1404 Registered Member Join Date: Mar 2016 Posts: 1,821	Increased flow caused algae growth on Montipora Hello guy, Couple of week ago I increased the flow in my SPS tank and rearranged the power heads. I did this mainly because I was not satisfied with the growth patterns of several montipora even tough they were growing and healthy. Digitatas were growing nicely but they were producing very this branches. Here I mean like very very thin branches, I had several cases where fish bumped into and broke them (it was a good natural fraging, now I have 3 colonies ). On top of that, they seemed to be more intrested in encrusting than producing branches. Other encrusting&spiking montis like spongedas and setosas were mainly encrusting and were only producing very short spikes. I interpreted all these as sings of low flow, since SPS corals generally behave this way when flow is low. Anyway, after I increased the flow, several weeks later I observed algae growing on top of some montis. I would not say the flow is direct, it is generated by two wave pumps and one gyre pump, so there is very little to non laminar flow and it is extremely random. Total turnover rate is close to 100X. One digitata has small patch of algae growing on a "stopped growth tip", as well as on the side of one of the branches. But aside from this the coral looks healthy. It has full polyp extension.and even the sites that have algae on them still have their polyps. During the day it is hard to see the algae as open polyps cover them. But at night and early morning, before polyps open, I can see patches of brown algae. There doesn't seem to be noticeable tissue recession, but the fact that algae can take a hold on make me believe there probably is. In addition to this, one spongeda has tissue recession at certain regions which get brown algae on them. It is not widespread, there are just few small spots, mainly "old regions" that are shaded by the spikes. Here by old I mean parts of the coral that are found towards the center. Younger, newly encrusted regions and spikes dont seem to get algae. Paradoxically, a nearby purple stylophora, an acro that gets brutal amounts of flow and certain other digitatas around seem to be okay. So this makes me question if it is a flow issue, or simply coral "gave up" on certain regions with the change in the flow. You know as coral colony grow, regions that get no light, or no flow eventually die out, even though the colony is healthy. In your opinion, should I change the flow or reduce it, or should I ignore the algae and wait for the those corals to acclimate to it? Like I said before, aside from the several patches of algae, the colonies doesn't look stressed or unhappy and are actually growing at other sides. As of right now the only this I do is to try to blow away the patches of algae with a pipette. But since they already grow on a coral that gets good amount of flow, it is very hard to blow then and I am wondering if trying to blow them away causes more tissue recession.