UV Sterilizer (1 or 2?)

[peterac]

I am setting up a 450g marine tank and I plan on installing a UV sterilizer. According to my research I should be going with a 60 to 80 watt output for maximum effectiveness.

Here's my question:
If I go with 80 watts, would there be a benefit to getting 2 40 watts instead. I will have 2 return pumps from my wet/dry so I could put one on each return line. Or would I be better off with one 80 watt providing a stronger UV output? The only reason I would consider the 2 UV setup would be for redundancy and backup. I imagine that 2 40s will cost more than an 80 as well.

Thanks,
Pete R.
Malverne, NY

[quarryshark]

For a UV to be effective, you need to have a slow water flow through it. Whatever its GPH rate, try and stay towards the middle of the high and low flow numbers that the manufacturer gives you.
No need for backup, its not something you have to have running. If its cheaper to go with the 1-80 watt, I would go that route. IMO
With the use of proper qt for your fish, parasitic outbreaks should not be a factor anyway. If that is your reason for running one.

[seaham358]

Why are you looking at getting them? This is a item that you do not need, but is nice to have for piece of mind and it helps with free floating algaes.
hooking them to the return pump is not a good idea becasue the flow is too fast, they will need there own pump to be effective.
450 gal tank thats a BIG system.... Why a wet/dry over a sump? What type of skimmer are you looking at? Is this going to be a reef or FO tank.

[mojoreef]

40 watts should be good enough to kill what you are looking t kill, I would get the two that way you will have longer contact time to do the damage. As mentioned above slow flow is critical.

Mike

[peterac]

I am thinking the one 80 watt is the best choice here. And also it seems that I should not install it inline with my main returns. I will be using 2 Aqua Sea 2100 pumps to return water from my sump.

Regarding the last post: I guess i am not up on the exact terminology. My main filter is a large sump half filled with bioballs. I thought this is the same thing as a wet/dry or trickle filter? Let me know...
It is going to be a FO with 300 lbs. of LR. As far as a PS I am also trying to figure that out. I saw an ASM G5 on eBay for $530. What do you think? Suggestions are more than welcomed.
Yes it is a huge tank, but if I take it slow and stock with caution I think in the long run I will find that keeping it stable will be easier than a smaller tank. I got it for $2,000 from a family member (with wood cabinet). I could not say no!

Also, regarding the fact that I should not put the 80 watt UV inline with my main return. Any suggestions for a dediacted pump for the UV? The tank is acrylic with 2 large oval openings on top that have removable acrylic covers to seal them. The main intake for the sump is at the back of the tank through 2 separate towers (gravity fed). I am not sure how i could plumb another pump for the UV without drilling/cutting into the acrylic. Could I run the UV from the sump if I am already coinsidering running the PS from the sump?

Thanks a bunch,
Pete R.
Malverne, NY

[quarryshark]

I run my UV from my sump with a separate return pump. My pump is a mag 5 with a flow of 500GPH..nice and slow. I have a 40watt, for an 80 you may need a different GPH rated pump.
Would have to see a pic to figure our how you would return the water.
Also with the #300 of rock, I would loose the bioballs. Nitrate factory.

[peterac]

Thanks. Maybe I'll try to get some pix for better input.

Rgarding the bioballs plus the LR being a Nitrate Factory - I have heard this sort of take on the subject before, however, just thinking out loud hear, if you want your ammonia and nitrite levels to be zero how could additional surface area for nitrifying bacteria casue excess nitrates? In other words, once ammonia and nitrite levels bottom out there is nothing left to cause excess nitrate buildup? Maybe I am missing something. I took marine biology classes over 10 years ago and I am finally getting this huge aquarium up and running so I am not on top of my game yet. Yet!

Thanks,
Pete R.

[quarryshark]

Excess nutrients will accumulate on the bioball over time raising your nitrate level. They are not really needed or IMO desired when you have a sufficient LR surface for the denitrification to take place. LR is a more natural and self sustaining filtration system and the bioballs will just end up being a nutrient trap. I slowly removed mine over time (didn't know better when I started) and my nitrites took a very sharp decline.
Believe it or not 300 lbs is on the light side of what your need for your system. It's a good start, but you will want to shoot for 1-1.5 lbs per gallon eventually.