View Full Version : Tridacna closed after return pump cleaned

11/29/2016, 07:01 AM
I've had this really beautiful blue Tridacna clam for about 6 months. He's been wide open every day with mantle streched out to the light. I noticed over the last three months that the return flow for one of my two eheim return pumps has been slowing. So I take out the pump and take it apart. Clean it with just running water and my fingers wiping away the grime. After I reinstall the pump, the clam has been closed. He's attached to a decent sized flat rock on the sandbed, so not so easy to move. Curious to hear your thoughts on what action I should take it any.



11/29/2016, 07:42 AM
If this is the only change to the tank, my guess is it's getting too much flow now and doesn't like it.

11/29/2016, 08:51 AM
Yes, thats the only change. Not sure how to correct this.
Its not so easy to move the rock he is on.

I could buy a smaller return pump?

11/29/2016, 11:34 AM
Don't buy another pump until you're sure it's the flow causing the problem. Is there a way to temporarily block the flow around him? If he's small enough you can use a piece of PVC pipe that's big enough to surround him or maybe stack some rocks around him to cut down the flow.

11/29/2016, 12:13 PM

This was last week.

Then he was completely closed for a day. Now today, he's halfway open.


Love that my wife sends me update shots of the tank, who needs a wed cam, lol.

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11/29/2016, 02:05 PM
Besides the mantle not being fully extended it doesn't look that bad. Check to see if the mantle is flopping around aggressively, if it is I would say the flow is too much for him and that's why he's not fully extending.

12/01/2016, 01:59 PM
Ok, update. I bought a small ball valve to lower the flow from the return pump.
Now the clam is opening a bit, but now I can see the mantle has some bits missing. The only recent addition has been a mollie Miller blenny. My wife noticed the blenny perched on the clam yesterday but I've not seen this. So are blennies not clam safe?

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12/01/2016, 07:35 PM
I have had mollies and clams and never had a problem. However, I wouldnt put it past a fish do something stupid.

12/02/2016, 04:45 AM
I've been chasing the blenny away when I see him near the clam with a blast of water with turkey Baster.

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12/05/2016, 07:30 AM
Now I've seen my Tomini tang go after the clam. I suppose its possible that the tang was just going after a bit of algae on the shell, but it was right at the opening where the mantle is. I did get a little lazy last week replacing the nori, so I've been feeding the fish a little extra and making sure there is always nori. Wonder what the thought is about a fish that gets a taste for clam? Is it something that may pass if the fish are well fed, or should I start thinking about catching a fish?