Clams as a filter

dwall174

Member
I recently read this Article by Dr. Richard D. Braley in Australia, about using giant clams as a bio-filter source for a aquarium! Has anyone tried this? & if so which clams would you use? I have read about using sponges & other filter feeders in a Cryptic Zone Filter But this is the first I have heard of the clams!
 

Maxx

Well-Known Member
I've known people to use clams as a means of reducing nitrates...but not as a sole means of filtration. Not that it cant be done, just hideously expensive for the desired result...meaning there are cheaper ways to do the same thing.
If you were going to be a first time clam owner, I would go w/ the Derasa clams. They are (relatively) hardy, require less light, and grow fast.
Nick
 

PSU4ME

JoePa lives on!!!
Staff member
PREMIUM
There are also non-decorative clams out there for this use as well....don't know the cost but i have 1 in my sump. HTH
 

dwall174

Member
Thanks!

Originally posted by Maxx
If you were going to be a first time clam owner, I would go w/ the Derasa clams. They are (relatively) hardy, require less light, and grow fast.
Nick
I'm working on upgrading my system this summer & I should have enough lighting for one then. I just have softies under 260-watts of PC light for now. I was just curious because that was the first time I had read anything about them used for filtration?
 

Witfull

Well-Known Member
ornate clams such as tridacnas when they are small are a particulate feeder, but once they reach approximately 3" they become almost completely self sufficient living off of their Zoox algae. this is what makes them excellent nitrate reducers, the algae feeds on the nitrates and inturn feeds the clam. so as a filter persay, they are not going to cut it, other bivalves will feed on freefloating organics, and assist in the breakdown process, but as to how many...my guess would be quite a few, which would add to the bioload of the tank, which means less of other life forms. not a good trade off in my book.
 

Crakeur

Member
I had a string of unfortunate events (fire and vacation flooding were the last two) and suffered a significant number of losses. Once I got things back up and running properly I was forced to take two large clams from a friend that was holding them for me. One blue dot sqaummy and one large black and white maxima.

I put them in the tank and the two clams thrived in the crappy water. about half an inch of shell growth, maybe more, in a very short period. I added a third clam (purple crocea - gift from a friend) and the results were the same but the growth slowed a bit (thank god).

So I will say yes, you can use them as a filter.
 

ScottT1980

Well-Known Member
This line of thinking was similar to what I was thinking with the local sea squirts on our coast. I have been thinking about adding a few to my sump to experiment with them as another part of my biological filter. My only fear with both the bivalves and the sea squirts is that they might only filter out particulates (instead of nitrate uptake, something that the mangroves and macro algaes are able to do). So, particulate filtration can be a good thing but with my softy tank, I worry that it might take away from my corals. Of course, I have a skimmer that does the same thing so who knows...

Take er easy
Scott T.
 

sorcerer

Court Computer Wiz
Where is mojo when you need him? Mike and I had this talk as part of a thread on RAG sometime ago. Bivalves do filter the water but as with any bioogical filter, the also produce waste. For tridacnid clams you wold tend to get an overall null effect. Some other clams and oysters filter nitrates and ammonia better and can also trap heavy metals in their tissues as they filter. Oysters can be particularly good at capturing lead and mercury.

Based on what I have read, to be effective you would need a refugium of a substantial size with a large number of clams or oysters that could be harvested on a regular basis to have any successful filtering. In the long run macroalgae in the refugium would be more effective in filtering and costs. Also easy on the harvesting issue.

I currently have 6 different tridacnid clams and a hippopus in my 75G and instead of aiding filtering I find that for them to be really happy I need to be between 5 and 10 on my nitrate reading. While the clams do fine I don;t really think that they aid that much in filtering.
 
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Dingo

Member
Think of the lengths that the average SW aquariast goes to in order to reduce nitrates. Large water changes. Denitrators. Deep sand beds. Tons of live rock. Starvation feedings.

Along comes an ornamental beauty that excels at reducing nitrates. Why wouldn't you use clams as a key component of your biological filtration?

When we talk about biological filtration in our tanks, we are almost always talking about the Nitrogen cycle. Clams are good for reducing nitrates. They address one of the most difficult long term problems in our tanks, the buildup of nitrates over time.

Too bad you need such strong lights, but many reefers have the lights anyways, so it's no big deal.
 
In my area, the rebound of healthy clam beds in Barnegat Bay has helped clean the water and reduce toxins and pollutants in the estuaries. Now that the water is cleaner, the clams are polluted because of the toxins they have absorbed into their flesh. It only takes some time for the clams to filter clean water until they are edible again. I only see good things by throwing a couple of burrowing clams into a deep sand bed fuge.
 
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