Deep Sand Bed

[johnkristie]

I've got a 200 gal tank with a reverse flow undergravel system on it right now, along with overflows to a sump that contains bioballs. I have two pumps running the system, one Velocity T-3 (800 gph) running the undergravel and a Velocity T-4 (1200 gph) running the overflows and sump. My crushed coral sand bed is about 3-4 inches thick. The coral sand is not the real fine stuff, but more course. My tank has been running fantastically now for about a year. No fish casualties and all the fish are extremely fat and happy. The only thing is that I have some moderate brown algae growth and my nitrates run right around 12-15. I am thinking about getting a skimmer and running it partially off of the Velocity T-3 that is currently running the undergravel. I guess my question is, if I cutback on the flow to the undergravel to support the skimmer, will my crushed coral sand bed turn anaerobic? And will that be a good thing or a bad thing? :?

 

[phases99]

sorry, please ignore

 

[fishfreek]

It would be a bad thing. For corse crushed coral to go truely anaerobic the depth will need to be more than what you have anyway. Your biggest issue will the the collection of detrius that then breaks down into nitrate. Im quite suprised at your nitrate levels only being in the range they are.

 

[johnkristie]

So then I probably should NOT run both the undergravel and skimmer off the same pump, but run the skimmer off its own. The only thing I'm kind of worried about is the temperature that will be added with a third pump, especially a submersible. My tank already runs at 79-80 degrees with no heater. How much more will it go up with a third pump added to the system? Also, is a 12-15 nitrate level too high for a fish only tank. I know it is for a reef tank. The new skimmer should bring the nitrates down quite a bit I would think.

 

[indy]

To have an UG and CC substrate with only 12-15 is downright amazing. Its fine for FO and for a majority of corals as well, excluding sps and other hard to keeps. That combination should have nitrates around 120-150. How light is your bio-load?

 

[johnkristie]

I've got a Medium Passer Angel, Flame Angel, 3 Perc clowns, Yellow Tang, Foxface, Royal Gramma, Longnose Hawk, and 3 Yellow Tail damsels. Maybe I should take a sample of water into my LFS to verify the nitrate level. And how about that temperature question, will another pump raise the temp too much?

 

[nutrak]

a pump shouldnt raise the temp at all. definitely consider getting a skimmer going somehow though...its a big plus. you'll notice a difference right away.