Vacuming sand bed

[clevan]

I've got crushed coral, about 3 inches deep, and I've been vacuming it the past 6 months but fear I may be vacuming too much (stiring stuff up). I've also noticed an increase in algae and what appears to be cynobacteria over the past month (nothing else in the tank has changed). Just how much vacuming is too much...meaning how deep?
Thanks for the help

 

[mr_X]

i think you are not vacuuming enough if there is still stuff to be stirred up.
make it as clean as when you put it in the tank.

 

[clevan]

I always thought if you vacumed up too much you would be disrupting the bacteria and messing with your biological filtration?

 

[mr_X]

i really don't think your crushed coral constitutes a live sand bed. the granules are too big. i'm afraid all crushed coral does it trap detrius.

 

[clevan]

I guess I'm confused when I first started the tank around 6 months ago, I bought the bags of what I think was called live sand (sealed with water in the bag)...maybe I'm incorrect when I refer to it as crushed coral. What I do know is that it's not just normal sand.

 

[mr_X]

ooh
if it's not crushed coral, which is large (about the size of BB's) and you purchased it in bags labeled "live sand" it's probably sugar sized aragonite. i honestly don't vacuum mine ever. whatever my sand dwelling creatures stir up is what gets stirred up.

 

[mr_X]

also, i'm not sure, but i think you might need your DSB to be a little deeper. i'm told 4" to 6" is most effective.

 

[clevan]

Thanks for the info Mr. X

 

[SnowManSnow]

I have argonite, and clean it whenever I get a chance

I don't think its possible to suck the bacteria off your rocks.

b

 

[Anonymous]

I guess I'm confused when I first started the tank around 6 months ago, I bought the bags of what I think was called live sand (sealed with water in the bag)...maybe I'm incorrect when I refer to it as crushed coral. What I do know is that it's not just normal sand.

No, you're NOT confused. The nitrification process, also known as biological filtration, is achieved by bacteria that are attached to surfaces. One of the areas that you'll find large populations of such bacteria is in whatever substrate you lay down. It does not matter if it's sand-sized particles or rocks as big as your fist. It matters if you over-do it, though.

Now, for the vacuuming, what you don't want to do is vacuum the entire bed, no matter WHAT it's comprised of, at one time. At most (especially with a new system) do 1/3 of the total substrate. Do vacuum the entire depth assuming you are not running a DSB (deep sand bed as Mr. X described).

If you find that you're suffering peaks in ammonia levels after vacuuming, then you know you've done too much. But, if the tank's already up and running fairly well, go ahead and vacuum the substrate as I've instructed, and doing so as frequently as once a week is fine (is preferable, actually). Making it part of a few large water changes may help the cyano outbreak.

 

[mr_X]

It does not matter if it's sand-sized particles or rocks as big as your fist. It matters if you over-do it, though.

sure it does. the amount of surface is certainly an issue.
crushed coral cannot be used as a deep sand bed because the large spaces between the granules hold more detrius than the bacteria can compete with.

 

[FinalPhaze987]

sand stirring creatures may help...ive got a dragon goby that leaves no grain unsifted.... i would suggest waiting until your tank is a little more matured before getting such an animal, but it can help in the future. increasing flow helped me when i had the same problem as well...the higher flow didnt allow anything to settle in the sand so it all eventually ended up in the sump where i was able to vacume it out. hope this helps...good luck!

 

[Anonymous]

It does not matter if it's sand-sized particles or rocks as big as your fist. It matters if you over-do it, though.

sure it does. the amount of surface is certainly an issue.
crushed coral cannot be used as a deep sand bed because the large spaces between the granules hold more detrius than the bacteria can compete with.

if you're vacuuming the bed, then the size of the granules doesnt matter one whit, as you're removing the detritus in the first place.

Vacuuming a DSB nullifies the entire point of a DSB to begin with- by sucking up the sand to pull the detritus out, you're destroying the anaerobic areas(bottom most layer of the DSB) where the denitrifying bacteria thrives.

 

[SnowManSnow]

i guess it may help to think of a DSB system as a sort of plenum. The same principle applies, in that you have an area underneath everything that is suppose to work like a hidden factory to clean things up.

Most ppl don't run a plenum system anymore.... so why do they run DSB? Isn't it just a plenum filled with sand?

b

 

[Anonymous]

It does not matter if it's sand-sized particles or rocks as big as your fist. It matters if you over-do it, though.

sure it does. the amount of surface is certainly an issue.
crushed coral cannot be used as a deep sand bed because the large spaces between the granules hold more detrius than the bacteria can compete with.

It doesn't matter what size the particles are in regards to the benthic bacteria associated with nitrification, i.e. the oxidation of ammonia. Nowhere did this person say that they're running a deep sand bed prior to our posts. I still don't know if they're running a DSB, do you?

Believe it or not, I've seen "DSBs" comprised of coral pieces as large as 3/8" in diameter and are clearly pieces of coral. Those beds had lots of worms in them, I don't know if they actually performed DEnitrification, but the readings of nitrate were zero in these systems, no cyano, bristleworm, or diatom outbreaks, so something was being done right.

 

[mr_X]

bristleworms are no indication of denitrification. actually, i would say they are an indication of excess detrius.
and as for your 3/8" granule dsb's denitrifying qualities...i'm willing to bet that tank was full of live rock. :wink:

 

[Anonymous]

Ya think? :| Now... where was the bit about bristleworms posted...?

 

[mr_X]

Believe it or not, I've seen "DSBs" comprised of coral pieces as large as 3/8" in diameter and are clearly pieces of coral. Those beds had lots of worms in them

 

[Anonymous]

Believe it or not, I've seen "DSBs" comprised of coral pieces as large as 3/8" in diameter and are clearly pieces of coral. Those beds had lots of worms in them

I still don't see "bristle" in there... :?

And we still don't know if the original poster is running a DSB or what.

 

[mr_X]

what kind of worms should we be looking for then, to tell us if our sand beds are aiding in biological filtration?