Advice needed on sand bed cleaning

[WABlonde]

I have a 75 gallon set-up with about 2-3" of sand. Current tank occupants are only a few corals, a hand full of snails, few shrimp and an emerald. All the fishies are in a QT tank and still have a few weeks before they can return to the display.

I want to take this opportunity to give the tank a GOOD cleaning. In the past, we've made the mistake of moving rocks around and lost our wrasse from the nitrate spike. I really want to avoid making this mistake again - but also want to do what I can to prevent nitrate build up in the sand (if possible) and also keep it looking nice.

So my questions:

1 - If I go tearing through my tank, will the nitrate spike that is sure to ensue cause problems for my shrimp or any other inhabitants?

2 - going forward, what is the best way of maintaining my sandbed? i.e. how often should I vacuum/rake, how deep should I be vacuuming (surface only or really getting in there)?

Currently we do weekly water changes. We also added in 8 additional Nassarius snails as we only had one large one previously.

Really looking to you guys for your advice and expertise with this as we're not getting the answers we are looking for from our books.

Thanks

 

[BCT182]

I would never vacuum my sand. The nassarius snails do a great job keeping the sand clean. Also, a sand sifter works great because the turn over the top layer of sand without disrupting the biofilter. Sand sifting stars work well but are recommended for more mature sand beds as they can starve if there isn't enough detritus for them.


Posted via Tapatalk on iPhone 4.

 

[mojoreef]

WaBlonde I did a little write up on how DSB's work so take a peek and it should give you some idea on how they function and what they can and can not do.
DSB

Contrary to what most believe critters like snails/worms/stars will not clean your sand, they at most reduce waste about 10% and then poop it back into the sand (although they are critical for transmission). Sand is bacterial driven and the bacteria sets up zones that create the enviroment they require. In short the top 3/4 of an inch (sometimes less) is oxygenated and is safe if you stir it a bit, below that is the anerobic zone (or zone devoid of oxygen) and is filled with all sorts of nasties, stirring this will turn you tank into a toxic dump.
So this is your delemia, if you go to the bottom your going to subject your inhabitants to some nasty stuff, nitrates being the least of them. If it was me and I wanted to clean the sand completely I would remove all but the rocks and then shop vac it out of their and start over (save some of your top sand and water) . If you just want to do a quick clean on the top layer you should be fine, just dont go below a 1/2 inch or so.

As par maintaining, thats a tough call as a sandbed is design to sink end product and since theirs a bottom it will fill as time goes by. The best thing you can do is to try and reduce the amount of input (fish waste/ excess food and so on) so syphoning off the rocks, setting up a weeking schedule (or similar) to syphon out the top layer of sand? This will remove the waste load and thus slow down the fill. Your bacteria will only be slightly effected as they are mostly bound by biofilm to the sediment and their populations recover quickly.

hope it helps

Mojo

 

[WABlonde]

WaBlonde I did a little write up on how DSB's work so take a peek and it should give you some idea on how they function and what they can and can not do.
DSB

Contrary to what most believe critters like snails/worms/stars will not clean your sand, they at most reduce waste about 10% and then poop it back into the sand (although they are critical for transmission). Sand is bacterial driven and the bacteria sets up zones that create the enviroment they require. In short the top 3/4 of an inch (sometimes less) is oxygenated and is safe if you stir it a bit, below that is the anerobic zone (or zone devoid of oxygen) and is filled with all sorts of nasties, stirring this will turn you tank into a toxic dump.
So this is your delemia, if you go to the bottom your going to subject your inhabitants to some nasty stuff, nitrates being the least of them. If it was me and I wanted to clean the sand completely I would remove all but the rocks and then shop vac it out of their and start over (save some of your top sand and water) . If you just want to do a quick clean on the top layer you should be fine, just dont go below a 1/2 inch or so.

As par maintaining, thats a tough call as a sandbed is design to sink end product and since theirs a bottom it will fill as time goes by. The best thing you can do is to try and reduce the amount of input (fish waste/ excess food and so on) so syphoning off the rocks, setting up a weeking schedule (or similar) to syphon out the top layer of sand? This will remove the waste load and thus slow down the fill. Your bacteria will only be slightly effected as they are mostly bound by biofilm to the sediment and their populations recover quickly.

hope it helps

Mojo

Thanks, Mojo. I read through your other post as well which you referenced a 6" deep sandbed. I'm assuming the process is the same for a bed of 3".

Any tips on signs of when your bed is 'full' and no longer beneficial?

 

[mojoreef]

You have to look at it like its a sponge, so a 6 inch bed can hold more then a 3 inch. But the processes are the same. Its impossible to put a time limit on a snadbed as their are too many factors such as bioload, feeding, maintenance and so on. Usual signs are when you start getting algae outbreaks, usually starting from the sand itself or you are getting elevated nitrates even though all habits (feeding bioload and so on) remain the same. An easy way to see would be to do a test for nitrates and Phosphates in the water column and then right on top of the bed. If the bed is higher then you know whats producing.
One also has to remember that Live rock operates the exact same way as a sand bed (less effeicient though) the only difference is that its not restricted by having a glass/acrylic bottom so they can shed.

Hope it helps

Mojo

 

[BCT182]

Much better info mojo. I mis-spoke. I should have said the critters keep the sand stirred rather than clean.


Posted via Tapatalk on iPhone 4.

 

[mojoreef]

And that is a very important part of the cycle BCT, a huge part of denitrification is end product from one species of bacteria is brought down to the plate of the next bacteria for further reduction. Now bacteria do create channels (little hyways with in the biofilm) but nothing beats that worm holding its breathe and taking a dive!! They also help in keeping that top layer oxygenated and with out oxygen their would be no first two steps in the process and it would break down. They also do take up a portion of the composistion of the food/waste with them and fix it to their own bodies (they grow tissue) they problem is that they usuall die and then release it all back into the bed, lol

Mojo

 

[TheKraken]

WaBlonde I did a little write up on how DSB's work so take a peek and it should give you some idea on how they function and what they can and cannot do.
DSB

Mojo

I did not want to sully your DSB post so I will ask here: what about a remote DSB? I am pulling some sand out of the tank weekly as mentioned to thin the sand my display now that the clowns are stirring it up. Should I wash and store the sand in preparation for a RDSB? As noting settles in the RDSB it should stay healthier and it can be removed for cleaning without draining the whole display.

 

[mojoreef]

I did not want to sully your DSB post so I will ask here

Ah please do its how we all learn by talking about it. Every post on this board should be up for discussion.

what about a remote DSB? I am pulling some sand out of the tank weekly as mentioned to thin the sand my display now that the clowns are stirring it up. Should I wash and store the sand in preparation for a RDSB? As noting settles in the RDSB it should stay healthier and it can be removed for cleaning without draining the whole display.

If nothing settles in the remote sandbed then its useless and serves no purpose?? Unless I am mis reading what you are saying? The general concept for a sand bed set up for denitrification is to make it available to pick up what ever excess food or waste that is going to settle out in the aquarium. So when the sand is sitting on the bottom of the tank, those things natural fall out their. If the sand bed is in a different location?? and thus does not get all this waste it is ineffective? As in lets say you manage to get 50% of the products from the tank water and to the bed (which is probibly more like 5%) in a remote location, well what happens to the balance in the tank, you still need to deal with that?? Also a sand bed will contribute to an amount of food for the tank, it can help/create safe zones for little critters like posa and such to lay larvae, which can help feed the fish and corals. If its remote you wont get that benefit either or at least very little of it

Mojo

 

[TheKraken]

That DSP is front page materiel and my ideas are not fully formed on DSP. Your articles are helpfull.

The RDSP seems to be more of the sand in a bucket type with fast flowing water from a drain or recirculating loop. The fast flow limits the buildup of food so it is not a nutrient sink. However the dissolve nutrients are free to diffuse and undergo denitrification. For reference it seems like Calfo is a good starting point. I would like to know if you view this type of DSB or a DSB/refugiam as an advantage over DSB in the display.

 

[07FocusST]

From what I have experienced: Stirring the bed can spike nitrates and even can detect small amounts of ammonia. In my 55G I have 5 Nassarius Snails which are great, a cleaner shrimp, a Fighting Conch, Astrea Snails, Turbo Snails and Hermits. I used to have a sand sifting goby but removed it after the sand started to become more prestine.

 

[mojoreef]

Gald it helps Kraken. ok let keep talking

The RDSP seems to be more of the sand in a bucket type with fast flowing water from a drain or recirculating loop. The fast flow limits the buildup of food so it is not a nutrient sink. However the dissolve nutrients are free to diffuse and undergo denitrification.

Yes I am aware of the remote dsb. Ok lets start at the beginning, what we are all trying to do is to deal with waste and excess food that will build up in the tank and create nutrient problems and thus algae problems, so lets make sure we have that solidly in our mind set here.
Look at a dsb as something that continiously cycles nitrogen products (yes those only) until their is no nitrogen products left, the rest sinks. A remote is going to operate under the same concept, except its going to miss the vast majority of what we want to remove. Yes getting DOC's (dissolved organic compounds) it will do but those are very popular in the reef, everything likes those (corals, planktons, bacteria and endlessly on) so one could assume that most of them will be bound up in the tank prior to getting to your sand in the bucket, so no its still moe ineffective then having the sand in the tank. Plus it doesnt answer the question of what about all the waste and such that gets left in the tank.

Now the refugium, this is a completely different animal and serves a different purpose. This Refugium must be look at as a refuge (which is what it is designed to be) so it creates an enviroment free of preditors, good for growing bugs, good for growing algae for nutrient removal or to feed you fish. Yes it will take up some nutrients but it falls back in line with the remote dsb as per effectiveness.

So it brings us back to what our underlining concept is (getting the nutrient out of the tank) you have to physically remove them or remove the thing that has bound them (as in absorbed and add it to its tissue) thats it, nothing more, nothing magical just get it out...now, lol

Some folks syphon it out, some use algaes to bind it and then remove that, some get a bit with skimming, ozone and so on. But the bottom line is that it must come out and sand systems and Live rock do not do that, they cycle, then recycle the sink what they cant use.

mojo

 

[WABlonde]

I swear I must have one of the laziest goby's ever! She digs her hole under her rock.. and occassionally will dominate another cave (chase out another fish) but then back in she goes. She cleans around her hole but I never see her sifting sand anywhere else.

 

[mojoreef]

thats where you want that goby!! LR in your tank is kind of like a rock sitting in dirt, you lift it up and their is a buch of critter living under it. The goby goes their for protection but also to take advantage of all the critters that live under it, which in turn are feasting on all the shedding coming out of the LR. Its win win!!

Mojo

 

[WABlonde]

Nice! Okay - she can stay then.

 

[TheKraken]

For some reason sand sifting gobies are hard to find at my LFS at the moment. I wanted one but Rob had none to sell.

BTW, I was at the reef talk you gave at GSAS Mike. I am glad to see you are back in the hobby after ripping a seam.

 

[mojoreef]

Ahh cool, that was awhile back. Good to see your still in it also.

Mojo