Blue line nudibranch and powerheads
 

...just got one of these today since both my tanks have flatworms, one at truly plague proportions. What a cool little creature! I thought he was dead when he first arrived, but after 90 minutes of a 2 hours drip acclimation he started crawling around, and ate a couple planaria as soon as he went into the tank.

I have heard 'cover your powerheads' with these guys. My question is: how much suction is too much? I cut off my Korelia after I put him in the tank, but without it the tank barely has any flow (just the heater/chiller pump at about 5x tank volume -- hardly noticable, and maybe even less now that I covered it with a sponge)

I can barely feel the flow on the intake side of the Korelia -- is this still enough to cut him up?

There are different materials you can use to cover your powerheads that will have different levels of flow through them. I would look into perhaps trying a mesh fishnet material. Or there are baskets of sorts that you can put around it. I know sponges are common but those cut flow a LOT.

Thanks. The sponge I have on the other pump is really restricting my flow, as you said.

How small of an opening can these nudibranch fit through? Do they make themselves totally flat? (e.g., does it have to be a 'mesh' or can a slotted plastic grate do the trick?)

The trick is that you don't want enough suction to keep the slug pinned to the inlet, or whatever you have covering the inlet. It doesn't take much, as they nearly neutrally buoyant and don't have much of a way of attaching to anything. And yes, they can make themselves essentially flat.

Cheers,



Don

Well, it may be a moot point as after initially doing nothing but eat flatworms for the first 3 days (although not even making a dent in the population), he has been missing for the last 48 hours :( He definitely didn't get sucked into anything (since the tank has basically no flow) but I swear the flatworms have all come out to celebrate. There are more of them today than before!

They do not live long at all, and are very temperamental to acclimate. There can be tons of reasons, but he also might not be dead. Mine went into hiding somewhere, somehow for a few weeks and I thought he was a goner. Then a few weeks later I had no flatworms and my blue velvet was swimming in the water openly, which is common for a lot of nudibranchs and slugs when they are on the move for more food.