I have a 20 gallon standard good ol fashion tank and I'm thinking of keeping a couple clams in there now and need to know what sort of lighting and what not I should have. I plan on doing a MH pendant or fixture or something don't know if I need a 70w or 150w or more though (also if you have something that will work let me know)
how much light to keep a clam in a 20 gal
- Thread starter jsl6v8
- Start date
chrisstie
Premium Member
I'm not an expert and i'd check in the tridacnid and other mollusks forum on here but i think a 150w would be more appropriate- you can make a clam dull out if you dont accilmate it properly but once it is used to your light they like a lot of it.. i think a tad more than the 6 watts per gallon or so you can get away with when dealing with less demanding things?
Of course it depends on the clam andw hat not but there are a few threads in there that i've found very very helpful. There's a sticky with a great reefkeeping magazine article that talks about each type of clams needs too. Hope this helps!
Of course it depends on the clam andw hat not but there are a few threads in there that i've found very very helpful. There's a sticky with a great reefkeeping magazine article that talks about each type of clams needs too. Hope this helps!
Reefworkschris
In Memoriam
A 150 HQI is perfect but clams make a lot of waste and like really clean water so stick to your water changes and you should be fine.
nauti1us
ORCA President 2007~2008
Depending on what types of clams you want to keep will dictate the type of lighting that is required.
Maximas and Croceas need extremely bright light. I have never met anyone who has had "long term" success without metal halides.
Derasas and Squamosas can do without as much light, but still require good illumination. James Fatheree has written quite a lot of material on keeping clams in the reef aquarium.
From what your describing in regards to you tank, personally I would hang at least a 175W mH lamp. That way you have many options and the pendant would help keep the tank cooler than a standard canopy.
Matt
Maximas and Croceas need extremely bright light. I have never met anyone who has had "long term" success without metal halides.
Derasas and Squamosas can do without as much light, but still require good illumination. James Fatheree has written quite a lot of material on keeping clams in the reef aquarium.
From what your describing in regards to you tank, personally I would hang at least a 175W mH lamp. That way you have many options and the pendant would help keep the tank cooler than a standard canopy.
Matt
jay24k
Active member
Clams really live off the light. It has been speculated small clams require phyoplankton but it isn't true. You can supplement them but I haven't seen any proof they grow any quicker because of it.
There have been people who have purposebly had nitrates in their tanks because the clams will utilize them and help filter but a good clean tank works just fine.
There have been people who have purposebly had nitrates in their tanks because the clams will utilize them and help filter but a good clean tank works just fine.
nauti1us
ORCA President 2007~2008
Here's an interesting abstract released in 2004. FWIW, it’s been my observation and this is also documented that smaller or juvenile clams require additional nutrition than larger or more mature clams. Juvenile clams have not yet built up the level of zoozanthelle that more mature clams will develop. Therefore, the target feeding of DT's or having a higher organic content in the water column may in fact be beneficial to the survival of smaller clams.
In the 16 years of my reef keeping experience, I have had good success in keeping moderately sized croceas (3" +) alive and growing in size. While despite all my efforts, any clam I've attempted to keep (1" to 2") I've failed to keep alive for any sustained period of time... I attribute this to my tanks having extremely low levels of inorganic phosphates and little to no organic food supplementation.
Abstract Tridacnid clams live on coral reefs in the Indo-Pacific, in waters containing low concentrations of inorganic nitrogen. This study examined nitrogen flux in the giant clam Tridacna gigas. Adults and juveniles of this species typically occur with symbiotic dinoflagellates of the genus Symbiodinium sp., often referred to as zooxanthellae, which live in their tissues. Intact clams took up or released dissolved inorganic nitrogen (DIN), with the direction and magnitude of the fluxes dependent on clam size. Non-symbiotic larvae and newly-settled juveniles with few zooxanthellae released ammonium. Larger juveniles and adults depleted ammonium or nitrate from seawater, when offered separately. Rates of uptake of DIN, standardized to either clam wet weight or number of zooxanthellae, were highest in small clams (1 to 5 cm in length), and decreased with increasing clam size (>5 cm). Clams maintained in seawater containing high concentrations of ammonium (ca. 20 M) for 1 wk generally released ammonium in the dark and exhibited net uptake in the light. Freshly isolated zooxanthellae (FIZ) from small clams had higher uptake rates than FIZ from larger clams, implying that the latter may be more nitrogen-sufficient than the former. The gradient of nitrogen sufficiency in giant clams is related to zooxanthellae density, with peaks of both algal density and rates of uptake of DIN occurring in small sizes of clams, whose growth also appears to be limited by nitrogen availability.
In the 16 years of my reef keeping experience, I have had good success in keeping moderately sized croceas (3" +) alive and growing in size. While despite all my efforts, any clam I've attempted to keep (1" to 2") I've failed to keep alive for any sustained period of time... I attribute this to my tanks having extremely low levels of inorganic phosphates and little to no organic food supplementation.
Abstract Tridacnid clams live on coral reefs in the Indo-Pacific, in waters containing low concentrations of inorganic nitrogen. This study examined nitrogen flux in the giant clam Tridacna gigas. Adults and juveniles of this species typically occur with symbiotic dinoflagellates of the genus Symbiodinium sp., often referred to as zooxanthellae, which live in their tissues. Intact clams took up or released dissolved inorganic nitrogen (DIN), with the direction and magnitude of the fluxes dependent on clam size. Non-symbiotic larvae and newly-settled juveniles with few zooxanthellae released ammonium. Larger juveniles and adults depleted ammonium or nitrate from seawater, when offered separately. Rates of uptake of DIN, standardized to either clam wet weight or number of zooxanthellae, were highest in small clams (1 to 5 cm in length), and decreased with increasing clam size (>5 cm). Clams maintained in seawater containing high concentrations of ammonium (ca. 20 M) for 1 wk generally released ammonium in the dark and exhibited net uptake in the light. Freshly isolated zooxanthellae (FIZ) from small clams had higher uptake rates than FIZ from larger clams, implying that the latter may be more nitrogen-sufficient than the former. The gradient of nitrogen sufficiency in giant clams is related to zooxanthellae density, with peaks of both algal density and rates of uptake of DIN occurring in small sizes of clams, whose growth also appears to be limited by nitrogen availability.
jay24k
Active member
That is one person's experience though. If you check Barry at Clams direct and others in the clam forum, you will actually see it the other way. Perhaps our methods back then were not sufficient enough? There have been several of us that has grown clams from 1 to 2 inches without any additional use of phyto. Perhaps it is a lack of nutrients in the tank.
So far, really no one knows and no studies have been done in a controlled enviroment.
Still, it is a good read though and every bit helps.
So far, really no one knows and no studies have been done in a controlled enviroment.
Still, it is a good read though and every bit helps.
2 150 watt bulbs over a 20-30 gal would be a nice start. you cant do too much. 1000 watts over it would be better though as lomg as you keep it about 2 ft off the water. take your hot dog and turn it to liquid in a blender. add only a drop or two every other day in a tank that small
