dustins first tank. 120 gallon(lots of pics)

[fatman]

There are a of of ways to look at potential problems you may have and a lot of ways to deal with those problems. A sand bed over three inches deep, if made up of sugar fine sand, would make up for the use of small amounts of live rock, as you really are not all that short of rock when your intent is chiefly to house large fish. Fish will put up with water with much more organic nutrients in it than coral and other invertebrates will. A deep sand bed is a good bio system in and of itself. A lot of commercial frag tank systems use no live rock but use deep sand beds in large refugiums with algae and corals as nutrient exporters instead. A second skimmer would be an excellent choice for a tank with chiefly large fish. And then your live rock and sand bed would have much less organics to deal with allowing you the openness that large fish need. Your problem will be in if you decide to use more sand and therefore use the sand bed for a biological filter, you will need to stock your tank gradually (one large fish at a time or a couple of small ones) instead of in large spurts (3 or 4 fish at a time). This gradual method would also apply if you used base rock for the rest of your rock. This need to do things gradual is to give bacteria the time to colonize the new rock or sand to some appreciable extent. A second skimmer would allow faster stocking of your tank. Bio balls are not bad in a fish only or a fish only with live rock tank. However if you plan on keeping corals or invertebrates bio ball filtration is not a good idea.

[dustin_P74]

ok so as i have mentioned before im doing a mainly FOWLR tank and since i wanna optimize swimming space do you guys think it would be cool to move all the live rock to the back wall of the tank and make a wall of it or is that ill advised

[Bifferwine]

That would be fine, but just make sure that there is some water movement behind and in between the rocks. If you have them too close together or too close to the glass, crap will easily get stuck in between them and can lead to water quality issues. You want some flow to be able to move around the rocks. Most people have their rocks stacked up against the back wall.

[dustin_P74]

so if i got one of these http://www.drsfostersmith.com/produc...5&pcatid=15955
and put it back there i would be good to go on moving the rocks back to the wall

[Bifferwine]

Yeah, Koralias are a good brand of powerheads. You will need more than one for a 120 gallon tank though.

[dustin_P74]

so if i did two of them and put one on each overflow facing the rocks would that work. because i already have two of the ball joint water returns on each side but there close to the sides of the glass as you can see in the pics so that should work right

[fatman]

Originally Posted by Bifferwine

Rock is more effective for filtration than sand, since rock has much more surface area. Like others have said, if you are going to have big fish that poop a lot (tangs and angels) you should go with more rock.

How can a couple dozen large rocks have more surface space than millions of particles of sand. If live sand is not as or more effective than live rock it is not because of surface area. I guarantee there is more bacteria in a 5 or 6 inch deep sand bed than a typical load of live rock. Admittedly shallow sand beds are not as effective as live rock, but most people do not even consider a shallow sand bed as a contribution to bio-filtration, only as a cosmetic fixture. I only advocate a sand bed 1 inch or less, or 3 inches or more, preferably 5 to 6 inches. There is no doubt that a deep sand bed is a better denitrifier than live rock, as for nitrification I believe there is either a pretty fair toss up or that a deep sand bed would be the winner.

[Bifferwine]

I don't think he was going to add enough sand for it to be considered a DSB though. As he was asking, add more sand or add more rock, more rock will be more beneficial for biofiltration than a couple inches of sand.

[dustin_P74]

OMFG people im getting so frustrated with my tank. its taking so long to cycle. its coming up on a month now and the rites and rates are off the chart still, and whats really frustrating me is that the ammonia has been at zero for atleast two weeks now so when that happened i got all excited that the cycle would soon be over after that but the rites and rates wont freakin budge.

[fatman]

Water change. You do not need that many nutrients to cycle your tank or cure your rock. You are assuredly killing everything that came with your live rick but the bacteria that your breeding to break down the waste. They are important, but you should not kill everything just to build up as many of them as possible. If you have nitrates your tank is cycled, just not fully finished with the huge bio load it has been presented with. Once a tanks bio filtration system develops to the point of being able to produce nitrates from nitrites, which were produced from ammonia, then the system is developed. However it is still overloaded. If nothing else look at the fact if the nitrites were not so high you would not still be killing organic organisms that are still feeding your cycle which is keeping the nitrite readings high. At the present rate buy the time you quit producing nitrites you will have nothing in your tank but the bacteria and a few resistant strains of coraline algae at best. Read the article here on curing live rock http://www.tampabaysaltwater