SPS WPG = 7 1/2 OK?

[KMTaquarium]

is 7.5 WPG good enough for a SPS propagation tank?

 

[2poor2reef]

IMO watts per gallon means very little, especially with smaller tanks. A 10w bulb over a 1g tank would support nothing. As you scale up in size it still doesn't tell you much.

Even besides wattage, the color temp of the bulb itself is also a significant factor. Personally, I use a 250w 10K pendant over my smallest (15g) sps prop tank. What would that be, 17 wpg (I'm guessing) and I wouldn't use anything less. See, so wpg doesn't mean much.

 

[SeaSydney]

I am also imtrested in knowing if I could keep sps and since WPG isnt a good indicator then let use a particular tank setup to determine if I can.
56 gal tank 30"l x 18"D x 24"H.
3" LS bed, 90 lbs LR
2 x 175watt 10K MH
2 X 75watt attinic VHO
Tatal wattage 500 = 8.9WPG
Cal and Alk at optimum levels

Would a tank like this be able top house sps corals?

Thank you Mark 8)

 

[2poor2reef]

Hey Mark. I'm sure someone will say that they do very well with 175w mh but I would run 250w or more. However, there are a lot of other considerations. First, not all sps require the same lighting. Pavona is classified as an sps but I have kept it under less then strong illumination and it has adapted well. There may be other specific species that don't require strong lighting also.

Second, even within the same species, some specimens grew under lower lighting levels than others. These could have been collected deeper or in partially shaded locations. Captive grow frags are also often adapted to lower light levels, relatively speaking, versus natural sunlight.

Third, you can sometimes make do by careful positioning. Placing something 9 inches directly under a 175w mh is quite different than 18 inches deep.

Anyway, I like to run a little more wattage than 175 but others may give you better info on that particular wattage/bulb temp. Enjoy.

 

[ColdZero1]

If you could I'd go with some bulbs that have a little more power for the depth of the tank you are using. 175w halides aren't going to be very bright at the bottom of a 24" deep tank. I'd go for 250s if you could. The cost difference really isn't that much and you'll be able to keep more stuff. If you are building this, the ballast difference is like 10 bucks and the bulbs cost around the same as well.

 

[KMTaquarium]

once again ive changed my prop tank dimensions
Dimensions are
Length 48"
Width 24"
height: 6"
lighting is 2: 110 watt 50/50's or aquasuns(havent decided). vhos' hovering/hanging 4" off the top of the tank

 

[Marcosreef]

If you are building this, the ballast difference is like 10 bucks and the bulbs cost around the same as well.

Although this is true, keep in mind energy costs.

Regards, Marco

 

[Sue Truett]

I totally agree that watts per gallon has no meaning in the keeping of sps corals. The key is lighting intensity. I use 65k iwasaki's in both 250w and 400w. I have nice color and like the 250w more than the 400w as they are too much IMO. Of couse if you have a shallow tank height then you don't have to blast the corals/frags to get nice color. 175w MH's are going to be hard to light a 24" depth. I think a 250w MH would be a better choice and a 10k or 65k. Also something to remember is that water has got to be stable to house sps corals effectively. Calcium and alk. levels need to have stablized and if not the lighting won't matter. I'm interested in trying the 250w DE 10k HQI. Heard some great things about these lights and the 400w radiums on a HQI ballast sound and look awesome too.

my 180 ecosystem sps/clam tank:
http://berlinmethod.com/suet/
my 120 ecosystem sps/clam tank:
http://suetruett.homestead.com/home.html
www.marshreef.org/members

 

[ColdZero1]

250-175 = 75 * 2 lights = 150 * 10 hours = 1.5kw more a day which is like 12 cents where I live, or around 25 cents in CA, which * 30 = 9 bucks more a month for me.