Survey Reefers re: vacuuming sand bed.

[jda]

In a saltwater reef tank, all that anoxic bacteria need is nitrate, no oxygen and an electron donor (which can can come from many things).

The next time that I need to worry about sewage, there is for-sure no shortage of studies and papers out there. It has been written for decades about how not all of this translates to our situations at all.

How do I know that my sand complete the nitrogen cycle? FOWLRs with nor coral or algae that kilos of fish food a week with sand beds still have .1 no3.

I know that switching zones can be bad... which is why I posted about not messing them very often... and then allowing them to rebuild before moving on.

 

[BeanAnimal]

That wasn't my question to Alexraptor though. My question was: What is his definition for aggressive filtration? In numbers. This is a genuine question.

I think the answer is going to be rather nebulous and subjective, as I somewhat asked the same thing.

I do think that you can over filter, but that is a broad subject somewhat outside the scope of this thread.

Also the feather dusters disappeared after the introduction of the reef mat filter. He didn't even add any other fish for one year. Sure there may be other reasons and conditions but one significant one is starvation.

I don't disagree, I also don't believe that a filter roller can be that effective. One would presume there is a lot of "food" left in the display even if the mechanical filter is inline between the sump and display. I suppose it could be the tipping point in a broken chain or a direct cause. That bring us back to the first question, and I think the answer depends on the system.

 

[sfin52]

#MODS thanks

 

[sfin52]

I stir the sandbed during water changes and right before I clean the filters. This is done when my wrasse is out and about.

 

[Tavero]

How do I know that my sand complete the nitrogen cycle? FOWLRs with nor coral or algae that kilos of fish food a week with sand beds still have .1 no3.

Thanks. That's an important condition which you should have specified earlier. Would have made discussing specifics easier. In that case you may have denitrification in your tank. It doesn't change my other arguments though.

In a saltwater reef tank, all that anoxic bacteria need is nitrate, no oxygen and an electron donor (which can can come from many things).

We are still talking about denitrification right? Then that statement is wrong.
First, you need to differentiate between anoxic and anaerobic.
Also, Sewage or reef tank these are the same microrganisms. So in my opinion they do translate to our situation.

A carbon source is obligatory in addition to the electron donor, which in case of denitrification, has to come from oxygen and nitrogen.

One condition is energy consumption

As you can see the energy gain is lower the higher the bacteria needs to go in the denitrification chain. This is tested while offering Glucose as a carbon source. Without carbon no energy.

Another conditions is pH.

If the pH drops below 7 due to low water flow caused by clumped sand particles, then hno2 will start to inhibit denitrification.

These are just two examples because you said: all the the bacteria needs is nitrate. Which isn't true. Denitrification may actually happen in your tank, but I still think that's a rare case in the majority of reefs tanks (at least in significant amounts)

 

[jda]

...and an electron donor. This has been written about for decades and studied in tanks and not sewage treatment plants. Put in 3+ inches of sand, leave it alone and it will lower nitrates in time. Worked since before most of us were born. h2s is still not a problem either in our tanks in nearly all cases.

 

[Tavero]

I think the answer is going to be rather nebulous and subjective, as I somewhat asked the same thing.

I do think that you can over filter, but that is a broad subject somewhat outside the scope of this thread.

Sure I was just interested because I never filtered my tanks but now I want to begin to use some sponge filters with 300 l/h flow to reduce detrius and particulates.
Is that already aggressive filtering? Probably not. But where does it start? I also don't want to neglect my sand bed again as I have done in the past. Therefore I try to vacuum as much as I can during water changes. Is that aggressive cleaning. Maybe but at least that detrius isn't clogging my sand bed.

 

[Tavero]

...and an electron donor. This has been written about for decades and studied in tanks and not sewage treatment plants. Put in 3+ inches of sand, leave it alone and it will lower nitrates in time. Worked since before most of us were born. h2s is still not a problem either in our tanks in nearly all cases.

What's with carbon? It's necessary for denitrification in my knowledge.

Well H2S was a problem for me when I started my first tank 15 years ago. Not in the sand bed but in the live rock. Maybe I was an outlier or maybe it's not as rare of a problem as you said it is. The whole rocks were black and smelled like rotting potatoes due to being stored in anoxic (not anaerobic) conditions.

 

[Alexraptor]

So what do you recommend?
You never specified a any filter size or filter duration, just said aggressive filtration. Now you just gave examples. When do you define aggressive filtration.

A friend of mine that runs a 200g tank introduced the standard red sea reef mat filter and over one year most of his feather duster worms disappeared.

It's not possible to reduce the filtration there. The system will change the floss by itself as soon it it clogged.

I think the answer is going to be rather nebulous and subjective, as I somewhat asked the same thing.

I do think that you can over filter, but that is a broad subject somewhat outside the scope of this thread.


I don't disagree, I also don't believe that a filter roller can be that effective. One would presume there is a lot of "food" left in the display even if the mechanical filter is inline between the sump and display. I suppose it could be the tipping point in a broken chain or a direct cause. That bring us back to the first question, and I think the answer depends on the system.

I mean, kind of, yeah lol.

I can't draw a line where filtration is aggressive and where it isn't, as that point is, by its nature, highly subjective and dependant on any number of variables. What I do know is that many aquarists generally run a whole battery of filtration methods in one system, such as roller mats, UV filters, protein skimmers, etc, and that to me is a clear cut case of "aggressive filtration".

I personally operate on the other end of the spectrum, I run most of my systems skimmerless and without any kind of continous filtration, beyond sand and rock.

And I agree, this is well beyond the scope of the thread. So to circle back to my opening statement, which seems to have set off the whole thing , all I'm saying is that I personally don't generally stir or clean my sand, and 'ideally' one should not have to take an active role in disturbing the sand bed.

Conditions however, aren't always 'ideal', and then one just simply has to find other solutions.

 

[jda]

You need OC to grow new bacteria, not for the existing ones to process/use nitrate. This is the same way with AOB and NOB - they need no new building blocks to just process nh4 and no2... just to grow new organic tissue. The denitrifying bacteria need an electron donor... any sort of organic. Some treatment plants use OC for this, but anything can work. If you are constantly washing away bacteria and needing to replace them, then OC might be a requirement, but that does not happen in our tanks where populations can slowly build and then stay relatively stable only needing minor tweaks along the way.

Every case of h2s that I have seen is from lack of flow and also lack of a diverse ecosystem. ...basically stuff rotting in place without being washed away and/or things to decompose/eat it. Surely I have not seen them all. I have had power heads fall and move massive amounts of sand down to the glass before and while this made quite a huge mess, there was not h2s to worry about - learned the hard way that magnets > suction cups. No tank has to make h2s, but I am sure that some do if they allow organics to move unprocessed into the areas without oxygen. If this happens, then the tank likely has more issues than just h2s.

 

[BeanAnimal]

I mean, kind of, yeah lol.

I can't draw a line where filtration is aggressive and where it isn't, as that point is, by its nature, highly subjective and dependant on any number of variables. What I do know is that many aquarists generally run a whole battery of filtration methods in one system, such as roller mats, UV filters, protein skimmers, etc, and that to me is a clear cut case of "aggressive filtration".

My reef is ~20 years old.
For close to 6 years there was no skimmer, no water changes, no ATS, no dosing (none)... NO FILTRATION. Just auto top-off.

There is now a skimmer and dosing Triton (3 part with trace). Still no ATS, no water changes, no mechanical filter.

I have toyed with the idea of a roller filter in a partial bypass setup .

 

[mizimmer90]

Hoping to add to the discussion that some argue aerobic denitrifiers are much more prevalent than we once believed.

The idea is that it's beneficial for many bugs have the ability to pursue anaerobic pathways when oxygen is scarce, though these pathways are still present even when oxygen is abundant. Apparently lots of strains can do this, and coupled with horizontal gene transfers, I'd imagine there's a lot of denitrification happening out in the open?

 

[JZ199]

I'd like to get a better variety of cuc or fish who stir the sand up, currently I just vacuum the top layer during water changes if it's nasty looking

 

[vetteguy53081]

As part of my tank ecosystem, I avoid disturbing it. On occasion, I will run siphon into spot areas to remove a little detritus

 

[Screwby]

I can see why people are mixed in their views. I have to say that when I had my fish only tank years ago I did vaccum the sand bed with every water change.

Now that I'm trying my luck at a reef tank with live rock and corals, I do vacuum it, but not as often. I think I learned some things along the way in the name of a clean-up crew. I think some of the sand dwelling inhabitants help with stirring and cleaning the sand to some extent. Nassarius snails, conchs, hermit crabs, sand sifting starfish, and even certain fish.

I guess it depends on your particular system and your bio load. Sometimes I do worry about catching a critter in the syphon tube, lol.

 

[LPS Bum]

I blow out my 1 inch sugar sand bed weekly with a turkey baster. The corals like it, and the ReefMat and skimmer pull out a lot of the junk in the water column. I think the trick is to do it regularly so that the detritus doesn't have a chance to build up.

 

[Ghostweim]

I stir and syphon it occasionally - I like to leave it alone as much as possible so my watchman goby and snails can have at it.

 

[BubblesandSqueak]

its been so long that I have vacuumed. but then again Jabber Jaw does it for me. My phosphates are feeding my GHA. I thought bubble bees ate GHA?

 

[gmflex]

Diamond goby , multiple urchins ,and snails.. I have 220 gallon tank.. The sand is super clean.. The goby makes the difference...

 

[Dburr1014]

Very interesting and I basically agree however after months of issues with dinoflagellates and nuisance algae I'm not sure how I'd approach starting a new tank if I did it again. Dry manufactured rock was great for creating a rock scape but I feel I'd like to use some ocean rock, at least in the sump if I did it again. Do you think that would significantly speed up the tanks maturation?

You can use wet rock to create a rock scape also. Aragonite sand and superglue holds just as well on wet rocks as dry rock. I have used this method on my tank scape to add a shelf here and there.