Cleaning sand bed?

A great example of how opinions can vary greatly in the hobby.

My view on the subject getting a little deeper than just saying "don't disturb your sand bed":

- Sand beds harbour both aerobic and anaerobic bacteria. By definition, aerobic bacteria need oxygen to live and survive. Anaerobic do not. But it goes further than this. Anaerobic bacteria either can't tolerate normal oxygen levels or get beaten out by aerobic bacteria in aerobic zones. If they could then we'd see anaerobic bacteria all over the surfaces of aquarium "stuff" and on the sandbed. We don't.

- When you shove a vacuum into your sand bed you the sand harbouring the aerobic bacteria mixes with the sand harbouring the anaerobic bacteria and some of the former ends up on the bottom of the sand bed and some of the latter on the top. This means that this portion of aerobic bacteria ends up in an anaerobic zone. It needs oxygen, doesn't have it, and it dies. This portion of anaerobic bacteria can't tolerate oxygen or gets beat out by aerobic bacteria and it dies. So by putting that vacuum in your sand bed you've just killed a portion of your bacteria colonies by putting that portion in a location where it cannot survive.

- If you're going strictly for looks and have only a shallow sand bed then to my knowledge vacuuming wouldn't affect you as much since you would be only hitting the aerobic "layer" (since there isn't an anaerobic layer). You'd lose some bacteria out the vacuum.

- There is debate that when you vacuum you remove a hefty portion of the bacteria along with the water going through the vac since the sand swirls around in the tube for a while, giving the bacteria a chance to dislodge from the sand. I'm not sure about that debate, but I certainly do believe that not all bacteria is attached to sand and a lot of it goes down the drain with the vacuumed water.

 

+1 on your assessment!

The only two questions I have are 1) does this apply to freshwater as well since the bacteria are virutally the same and 2) when you see detritus collecting in the corner of your tanks, and vacuum that up, you're not really vacuuming sand. So is this okay if someone does not disturb the sand bed just cleaning the dinoflagellets and detritus that can gather on the sand bed?

 

It does if you have sand. Gravel isn't quite the same because of the size of the rocks. You want to vacuum gravel to stop pockets of nastiness from growing.

Cleaning stuff off the top of the sand will not disturb the underlying bed. It's good to get that stuff because it can interfere with the aerobic action in the top layers of the sand bed. Enough can potentially cause stagnant areas which create "dead zones" of hydrogen sulfide. That's not good.

 

Honestly, I don't run sand in most of my systems. I do have sand in my display tanks as I keep nems and other animals that "need" a sand substrate...and frankly I don't like the look without it...but otherwise in the vast majority of our holding and prop systems there is no sand. It's much easier to keep those systems clean and healthy without it.

Absolutely...there are so many ways to achieve the same goal in this hobby...and I respect everyone's opinion.

Personally having run just about every conceivable version of a sand bed in my 25+ years in the hobby, I'll stick with siphoning, LOL! You'll never convince me there are enough Pro's to leaving it untouched...I've seen the nasty stuff that accumulates in untouched sand beds, and I will never believe that leaving that stuff in the system is a good thing. I've just seen to many "untouched" sand beds "fail" once they cannot hold any more nutrients...and I've seen many a "crash" or "partial crash" when people tried to remove the "expired" sand bed. I do know a small handful of people who have successfully run very deep sand beds for long periods (over 5 years), but I would say these are the exception...I also wouldn't say these are pretty/clean sand beds by any stretch, LOL!, but they do work long term in these particular cases.

Like I said, to each his own. If you are happy with your system and methods and how they work for you, far be it from me to tell you to do it differently. The vast majority of what we do in this hobby is based on subjective opinion not scientific fact, LOL!

To the OP, I would like to ask how deep your sand is? That in of itself may dictate if you should clean it. What we are really debating here is weather or not you should disturb deep sand beds of say 4" or deeper. If yours is fairly shallow you won't have the deeper anaerobic areas anyway.

 

WOW! I had no idea that this topic would be so controversial. I was so used to the look of a nice clean vaccumed sand bed in my freshwater tank, and I decided that is what I want in my salt water tank too. I am starting to accumulate some red algae in blotches around the tank, even where there seems to be flow happening. I think with tommorow's cleaning and water change I will be vaccuming some of those spots.