Read a ton of post on DSB's but still have a couple question

[jamal-188]

I've been reading a lot lately due to my ICK problem and would like to fix up my tank while the fish are in the Q tank. I read probably 20-30 posts on DSB"s but still have a few questions:

I do not plan on ever really having corals in my main tank(due to lack of money to light a 31" deep tank), pretty much fish/invert only, I assume a DSB will still be much better than my CC.

What size sand do I want, my LFS has different brands of sand the packages they have are:
1-7mm
5-10mm
1-17mm

Whichever I buy(which might even be playground sand if I can find it) should I get a pack of Live sand to mix in, or if I replace 1/2 my cc w/ sand and wait a week or two will that be ok.

Is there a calculator that will tell me how many pounds I'll need for 4-5" deep, tank is 48x18?

I've also been reading how wet/dry filters with bio balls are not very good? I thougth that was the best type of filtration?

Thanks again everyone, I really hope to have my tanks operating successfully again soon

 

[biotoxin]

If youre not going corals and live rock then a dsb doesnt matter. The ls and lr are the filtration so if you are doin fish only then a wet/dry is your filtration and a dsb would essentially be just for looks. I would be cautious when buying playground sound due to the high silica in it. Aragonite from a lfs or southdown if its in your area from home depot. You want sugar size grains of sand is what ive read. A dsb is best with very fine sand. As far as bio balls they are good for fish only due to their ability to produce nitrates in the wet dry filter. But a wet dry is not good for dsb or full reef tanks. I have ls with cc mixed in and its not a problem for me. I think your main concern is to just decide on what you want. As far as lighting a 31" tank i wouldnt really think its that expensive you want 3-5 watts/gal. Some corals done need tons of light where as something like clams do. Its up to you and what your plan for the tank is. What size is the tank anyway?

 

[ReefRaff]

Is there a calculator that will tell me how many pounds I'll need for 4-5" deep, tank is 48x18?

you can calclate your send depth here http://www.aquariumadvice.com/calcs2.php?type=sanddepth

 

[jamal-188]

If youre not going corals and live rock then a dsb doesnt matter. The ls and lr are the filtration so if you are doin fish only then a wet/dry is your filtration and a dsb would essentially be just for looks. As far as lighting a 31" tank i wouldnt really think its that expensive you want 3-5 watts/gal. Some corals done need tons of light where as something like clams do. Its up to you and what your plan for the tank is. What size is the tank anyway?

So a DSB is not good with a wet/dry filter, and it there is no real reason beside looks that I would switch at the point? I may eventually get a few pieces of coral and put them near the top of my aquarium but I only have a cheap $90 double florescent light until I can save up $200 for a 260watt aqualight that I'm gonna get. My tank is 110g.

 

[fishfreek]

The comments about wet/dry's not being good are geared toward Reef setups where we try to maintain low levels of nitrate. Wet/dry filters are excellent ammonia reducers and nitrite reducers. What does this mean? Well they will very quickly convert the ammonia to nitrite and then to nitrate but once it gets to the nitrate level tahts where it stays. The DSB goes one step beyond the wet/dry in its ability to remove the nitrates aswell.

What size of sand grain should you shoot for? Well I would say the smallest grain size you list is probably the best. Infact the famous southdown stuff is even finer than that.

Forgo the bagged live sand you see in the stores. AFAIAK is a waste of money and shelf space for the consumer. Its a big money maker for the companies that sell it and the LFS.

 

[jamal-188]

Ok, so I think I'll probably convert to a DSB even though I'm not sure about corals in the future, it will at least keep nitrates low for my cucumbers and starfish which my LFS said are sensitive to high nitrate levels. Thanks for clearing up what the wet/dry and DSB will actually do for a fish/invert only tank, that's what I was having trouble finding out in reading all these posts.

 

[wseaton]

Even though both my main tanks have DSBs, I'm still not convinced they perform as the perfect nitrate reducers without some help from LR and good circulation. I've simply seen too many bare bottom reef tanks with lots of fish and LR *and* with zero nitrates. My belief is that the truth is somewhere in the middle and that good nitrate reduction occurs both in good LR stocking combined with intelligent water circulation.

It's the reef tanks with enough sand to host a volleyball tournament and hide a full grown nurse shark that make me chuckle. Call me a MSB guy, or 'medium sand bed'. 4-5" should be plenty of depth to make nitrate reducing organisms happy and not contribute to the dreaded anoxic DSB time bomb.

DSB's work by creating a layer or 'zone' at a certain depth in the sand that is transitioning between low oxygen and no oxygen. It's this transition zone that accounts for nitrate reduction because the organisms that live there have to convert nitrate for energy vs oxygen. The reason sand is more popular than crushed coral is the fine sand creates this special layer at a more shallow depth because of it's greater density. You could, theoretically create the same effect of a DSB with crushed coral, but you'd need a *much* deeper layer of it.

If you've ever left a bucket of mature aquarium gravel that's been taken out of an established tank outside in the sun for a few days, you can see this in action.

I'm also not hostile towards bagged, live sand for reasons I've covered elsewhere. Dry sand such as ooltic is much cheaper, but it's also very messy for several months upon set-up and will fill up your filters with what best can be described as soggy drywall paste. Live sand has little biologic value contrary to it's marketing, but it settles much, much faster than dry sand. Does this mean you can save some money by using dry sand with a layer of live sand on top to keep it settled? Yep....and if you are going with a DSB use the finest size you can.

All this is anecdotal compared to the far more critical issue of nitrate reduction. I don't care if you are just housing African Chiclids, damsels, or a full reef. Low nitrate levels keep a healthier tank, indicate a healthy tank, inhibit algae and other organisms which destabilize PH, and drastically reduce the need for water changes. We might not be able to make up our minds exactly what method is best for accomplishing this, but if having a stack of LR on 4-5 inches of inert sand gets us there, who cares about the icky details??

I am not a fan of wet/dry filters unless I'm going to house a tank of 8,000 feeder fish, and even then a couple of Emperor back filters with bio-wheels are a lot less hassle. Same bacteria - same method of gas transfer. While I'm not opposed to wet/dry's or bio-wheels, I am convinced they aren't as efficient at nitrate processing as good old LR and power heads, and as mentioned above might inhibit it to a degree. There is one thing about that wet/drys I seriously don't like, and that's their ability to rapidly speed up water evaporation and hence increase the need for water top-offs.

 

[biotoxin]

good post wseaton . I have to agree that im not a wet/dry user myself. Too much risk of flooding during an outage and i live in an upstairs apt. Im sure the neighbors wouldnt like my live rock embedded in their entertainment center when the floor gives

 

[possum]

i have to disagree about the sand though. The playsand is ALOT cheaper and i have only had mine in my tank for like 2 weeks and it stays put just fine.

 

[jamal-188]

good post wseaton . I have to agree that im not a wet/dry user myself. Too much risk of flooding during an outage and i live in an upstairs apt. Im sure the neighbors wouldnt like my live rock embedded in their entertainment center when the floor gives

Actually if you set it up properly there is no risk of flooding. I flick the switch on my surge protector to shut everything down every day when I feed my fish.

 

[biotoxin]

true. i never knew about a siphon break until i came to this forum.