Acclimation 2 light


New member
How many days do you normally allow your clams to adjust to your lights?

Reason I ask is I put my new clams in the tank and put some cardboard over the top of the tank so they wouldnââ"šÂ¬Ã¢"žÂ¢t receive direct light. I was thinking this would take about a week and I would slowly give them more light every day. Well in 2 days they have moved out of the shade and into direct light and angled themselves for more direct light. So I just removed the cardboard figuring they had adjusted.

On a side note one moved at a rate of about one inch a day. I thought that was very impressive.

Calms say "a few days" so I was wondering what other clam enthusiasts do?
Well, there is really no definitive way to acclimate them to new light. It is really a judgement call. I try to find out ahead of time from what light source the clams have been currently under, and I use that as my starting point.

Once I have a "baseline" light intensity, I position them accordingly in my tank. If they were sitting under PC's, I'll place them in my tank as far from the MH's as possible, then move them closer each day. My new clams show discomfort by tilting to one side if the intesity is too great. I'll move them back a little until they are finally comfortable.

Seeing as how your clams moved so much, I am guessing you got smaller specimens, and they were eager to get under high light.
I usually evaluate how to place them by looking at the clam. If they are slightly faded in the center or show some transparency in the middle, I place them in partial shade until they darken up a bit.

If they come in brilliantly colored throughout with no sign of any low-light history indicated by a low concentration of symbiotic algae, I just put them right under the 250-watt halides on the bottom of the tank.

I usually don't run the lights the first day they are in the tank at all unless it is just actinic.

In the tank I house most of my new arrivals in, I have two 250-watt halides. One side is a Coralife 10k bulb, which is horribly dim (and blue) for a 250-watter. The other side is a USHIO 10k, which gives very high PAR- probably higher than anything but an Iwasaki as far as 250-watters go. This is not the most visually appealing thing, because I have two different colors (the USHIO looks more like 7-8k!), but this gives me the ability to gradually introduce them to the more intense light by placing them in weaker illumination and gradually moving them into the sunshine. I also have breaks in my rockwork that gives me some partially shaded places. I have seen clams that were VERY faded darken up nicely in a month or two by not rushing them into the intensity- I am sure a couple of these would have cooked their insides if placed directly under the USHIO.
Moving Clams

Moving Clams

The one that was crusing is about 2 1/2 inches from one side 2 the other. It's green when you look through the water level from above and a vibrant blue throught the glass. I wonder if I had starfire glass if that would change and the clam would appear green. Well I cant go wrong either way both colors a spectacular.

I noticed that the smaller clam shipped better is that normal? The other calm is twice as big and looked like shipping really stressed him out.

Thanks for the replys I appreciate it. They really increase the learning curve.
It is perfectly normal for the smaller ones to adapt better than the larger ones. In fact, a lot of people shy away from baby clams (under 3") because they require "extra" care. Babies also have a higher mortality rate than their big brothers and sisters.

But, the little guys are more resilient to change. I have a good number of 2" or less clams in my system right now - and they adapted much faster than the 4 and 5" croceas I got in the same shipment. They are a lot more conspicuous as well, if they don't like their environment. They can practically walk away with their single foot!

In general, if something goes wrong with your system, the big clams will be the first to go. As is the case with most creatures, adaptability decreases with age.

Unfortunately, the only way you can get the amazing colors clams are famous for is by viewing from the top directly down on the mantle. Starfire glass will not help you there.