Problem with micro algae dying - Copepods to blame?

[Corucia]

Dear all, I'm hoping that some members of the forum might have insights into a problem that I've had develop with one of my two three gallon shrimp ecosystems. I have had ~40 shrimp in each tank for about 18 months, with the shrimp in each tank accompanied by 3-4 hermit crabs and 8-10 snails. I have micro algae in both tanks, and in each tank (until recently) the micro algae flourished.

Now for the problem. Beginning about four months ago, in one of the tanks the micro algae started to die and in fairly short order literally turned pale green and distintegrated. After this happened, I took some of the micro algae from my other ecosystem (which is unaffected by this issue) and moved it to the tank where the algae died. Within a few weeks, the same thing occured. I subsequently bought another batch of micro algae from Petshrimp and introduced it into the problem tank. While it initially started to grow and appeared heathly, again within a few weeks it started to die and ultimatly disintegrated. I haven't had a similar problem with my other ecosystem, where the micro algae continues to thrive. Both tanks are essentially identical in terms of the colony, etc. and I use Zetlight LED full spectrum lighting in both.

However, there is one noticable difference beween my two ecosystems - - in the the tank with the algae morbidity, I have a significant population of copepods that has develped over the past 6-9 months. They have become partcularly abundant over the past 4 months, which is coincedent with the algae dying off. Moreover, upon inspection of the dying/dead algae under a 10x loop, one can see that the matter is laden with copepods which appear to be feeding on the decaying mass. Similarly, even before the algae began to die off, it had a volume of copepods surrounding it (perhaps feeding?). In the tank where I haven't had this issued, the copepod population is quite limited.

In any case, while the shrimp appear uneffected by the algae dye-off, I'm concerned that there could be a more ominous problem brewing. I'd be very curious to hear if other members have seen any similar issues and if they had a "cure" to the issue. All thoughts welcome.

[KenCotigirl]

The copepod explosion is due to the abundent food source, ie the dead algae not the cause of the dying algae. The algae is tough. I wish i could be more helpful. If you look closely there should some copepods in the 'healthy ' tank.

Ken

[Corucia]

Thanks for the response Ken. I do indeed have copepods in my second ecosystem, however they haven't proliferated in the same fashion that I've seen in the ecosystem with the microalgae issue. To your point, the copepod "bloom" is likely a result of the dying microalgae providing an abundant food source. To this end, should I be worried about the significant increase in copepod population? Will they negatively impact the Opae? Is there any remedy to curtail the copepod population (I've removed as much of the dead/dying algae as I could to cut back on their nutrients). Thoughts welcome.

[shrimpy4]

I echo Ken; I had my algae for a time, but my bowl was very small and it was a pale green that limped down and never seemed to grow. I bought a hermit and poured the water in, and suddenly noticed copepods in my water too. Within a couple of weeks, the algae went from limp to pale white and then completely disintegrated. Now I have a handful of growing strands of macroalgae, but I credit the copepods with breaking down and consuming the algae that was dead but just static with nothing to feed on it.

[Mustafa]

The copepods are harmless. I wouldn't worry about them.