How much pc light is enough for clams and SPS

[Anonymous]

Hi all,

Getting lazy and thought I could get an answer without researching.



I have 2 96 watt pcs over my 72 gallon. So far, all of my corals are doing quite well (LPS and softies). But I recently ordered 2 more 96 watters and I'm going to cram all four under my hood.

That will make almost 400 watts of pc for a 72 gallon.

I think with that much light, I could have some nice SPS corals if I place them mid to high in the tank.....right????


But can I put a clam on the sand and have it survive?

 

[Simon1]

I don't think thats enough light. That would be around 5.5 watts / gal. I have a little over 7 watts / gal, and thats not enough for clams. The clams might survive, but certainly would not flourish. As for the the SPS corals, I think you would have to place them really high in the tank, but it could be done with a few species.

 

[nanocat]

I've been told that by the time you'd buy enough PC to keep a clam happy, for the same money you might as well do it right and have MH.

I want one of those clams too...but sadly, I'm gonna have to wait.

 

[PeeJ]

MM...I disagree. Several well respect members of my local reef community stated that with my 520 watts of pc on my 100 gallon i could keep a few different varieties of clams...squamosa first comes to mind,

 

[ChrisRD]

Watts-per-gallon is a really a poor guideline as to whether or not you have adequate lighting for something IMO.

It's not how much water you've got that matters - it's how far the animal is from the lamp. In other words - larger tanks need stronger lighting to penetrate to the bottom of the tank because of their depth - not because they have greater volume and they need a certain watts-per-gallon.

Certain animals need adequate intensity to thrive. If you place a coral X inches under a given lamp, it doesn't matter how much water it's sitting in - it still receives the same intensity.

IMO 4 X 96 watt PCs (assuming good reflectors, good lamps, lamps close to surface, etc.) should be enough to keep just about anything in a relatively shallow tank like a 72 (assuming standard dimensions here). You'll probably want to keep the highest light creatures in the mid to upper parts of the tank.

Certain tridacna clams are said to do better under halides, but I don't keep them so I couldn't say for sure. Maybe someone else can offer something there...

HTH

 

[Cabreradavid]

The lighting you have is similar to one of the medium light intensity tanks I have. You should have no problems (at least with lighting) keeping T. squamosa or Derasa clams and Pavona sp. sps coral (keep it high in the tank). I have had no problems with these species. I would be cautious with other SPS (maybe others have input here) and would not try T. maxima or Crocea clams.

 

[ghofmann]

I just did some research on the subject myself and this is what I came up with: Sps corals have a certain amount of body mass that is devoted to food intake and a certain amount that is devoted to photosynthetic energy conversion. If one is supplimented, feeding for instance, then the amount of photosynthetic energy needed for the corals will be lessened.
According to Eric Borneman in his book "Aquarium Corals" he aludes to the fact that corals in captivity use more food and less light than previously thought. So what I got out of it was you can keep some sps corals under lower levels of light but you would have to suppliment with a feeding regime that might put a lot of extra nutrients into your system.

As far as clams go smaller clams rely more on feeding than they do on light, as the grow they rely more on photosynthesis. Squamosa, Derasa and Hippopus are less light demanding and may be able to be kept under less intense lighting.

 

[Anonymous]

Thanks all,

I'll take this advice to heart and try a squasoma or a derasa.

Can a clam be placed anywhere but on the sand? Can I wedge it between two rocks mid way up the tank?


I'm not a big clam lover myself, or SPS for that matter; I think they are over priced for something that might die...not that any coral has ever died in my tank, but $80 for one piece of coral or a clam seems a bit steep.

Unfortunately, or you might see it as fortunately :wink: , my wife sees money as no object when she wants something for the tank. :roll: She just says "can we have that"...I say "no"...she says "what do we need to do to have that"...I say "we need twice as much light".....she gets on line and orders two more 96 watt pcs and starts drooling over clams. :lol:


Thanks,

 

[Bobzarry]

For some time I ran a 55 with 4x96w PC setup. Yes everything did well enough, but it was not until I received 2x175w MH as a gift that I saw what a difference it makes. under the PC's the colors were drab. Within a couple of months of having the MH's my corals really colored up nicely and I am sure if they had been 2x250 they would be doing even better. Yes you can have growth and survival under PC's, but it wont be the same as a higher intensity light system.


Bob

 

[Anonymous]

Thanks Bob,

MHs are not an option for me, since I would have to hang them as pendants, and the tank is in my living room, so it has to look neat and put together. That means no open tops or lights hanging off the wall or ceiling.

Oh well....my next tank, when I get a house, will have MHs for sure.

 

[Bobzarry]

I have 2 hamilton pendants on my 55. what I did is cut opening on the top of the hood just about a 1/4 smaller then the pendants on each edge. The pendants now lay on top of the hood shining down into the hood.



Bob

 

[Cabreradavid]

You can still have a nice looking tank with PC lighting. Some of my very best looking corals are in a PC only tank (yes, I also have a metal halide/pc lit tank). So some specific comments:

1. With respect to clams, I would recommend a Derasa. They are the most forgiving and should be placed on the substrate. (other species do well in the rock work, but also need more lighting to do well) They need high calcium and good water parameters. As mentioned in another post, if they are under 2.5 inches you will have to feed them. I would suggest going to the Clams Direct forum and asking for their advice (provide exact lighting and dimensions of your tank) for more advice. My squamosa is doing great under PC lighting (but my tank is a couple inches shorter than yours).

2. With respect to corals, I would recommend against depending on feeding for your corals. I believe that the heavy prey capture Eric Borneman refers to is on actual reefs and not in closed systems like aqauriums (where such feeding is difficult to do). Most corals eat zooplankton, not phytoplankton. So feeding phyto keeps the food chain going, as opposed to feeding the corals directly. Unfortunately heavy phyto feeding could increase dissolved nutrients that can be exploited by nuisance algae. I suppose one could add rotifers and such to a tank, which would provide nutrition to the corals, but that is easier said than done. In addition, many of the very bright colors seen in SPS corals tend to go away when lighting is not sufficient. Others may be able to elaborate on this, but I think light is a pretty important factor for coloration regardless of coral predation.
The Pavona I recommended will do well high in the water column under pc lighting. The colony I have has grown well, if slowly, and has very nice bright green coloration. Others may have additional SPS coral ideas.

3. IMO, your SPS and clams should not cost $80. Try looking at frags.org for coral frags and a good price for a small Derasa should be under $50.

 

[Anonymous]

You can still have a nice looking tank with PC lighting. Some of my very best looking corals are in a PC only tank (yes, I also have a metal halide/pc lit tank). So some specific comments:

1. With respect to clams, I would recommend a Derasa. They are the most forgiving and should be placed on the substrate. (other species do well in the rock work, but also need more lighting to do well) They need high calcium and good water parameters. As mentioned in another post, if they are under 2.5 inches you will have to feed them. I would suggest going to the Clams Direct forum and asking for their advice (provide exact lighting and dimensions of your tank) for more advice. My squamosa is doing great under PC lighting (but my tank is a couple inches shorter than yours).

2. With respect to corals, I would recommend against depending on feeding for your corals. I believe that the heavy prey capture Eric Borneman refers to is on actual reefs and not in closed systems like aqauriums (where such feeding is difficult to do). Most corals eat zooplankton, not phytoplankton. So feeding phyto keeps the food chain going, as opposed to feeding the corals directly. Unfortunately heavy phyto feeding could increase dissolved nutrients that can be exploited by nuisance algae. I suppose one could add rotifers and such to a tank, which would provide nutrition to the corals, but that is easier said than done. In addition, many of the very bright colors seen in SPS corals tend to go away when lighting is not sufficient. Others may be able to elaborate on this, but I think light is a pretty important factor for coloration regardless of coral predation.
The Pavona I recommended will do well high in the water column under pc lighting. The colony I have has grown well, if slowly, and has very nice bright green coloration. Others may have additional SPS coral ideas.

3. IMO, your SPS and clams should not cost $80. Try looking at frags.org for coral frags and a good price for a small Derasa should be under $50.

I can get better prices on frags locally and small clams are quite cheap at my LFS, particularly because my guy gives me great deals.

However, the wife is against buying small pieces of coral or a small clam because of the time it takes them to grow. She would rather drop the $80 on a very large piece of SPS or clam...I guess I should consider myself lucky that she actually wants to spend more money on my hobby than I do.