Sand Bed Vacuum Test - Phosphate Liberation?

[The Cardinal]

Based on my personal observations from ca 6 years of reef keeping:

I notice a big difference in my tanks over the years if I do not siphon the sand (I have ca 2-3mm sand particles covering ca 4-6cm). Algae builds up on top of the sand and the particle matter is piled up in several parts of the tank if I do not syphon the sand. In areas of low circulation pockets of hydrogen sulfide can also build up with potential lethal results. The general health of the corals, better light reflection capability of a white sand bed and less smell from the tank when keeping the sand syphoned are other benefits to siphoning that I have observed.

I do not notice a lot of critters in the buckets when I siphon the sand so I am not worried about depleting the population (I also have an attached
refugium with overflow to my current tank). I also do not notice a higher concentration of microfauna in the areas where there is a build up of detrius and to me this indicates that the fauna is not particularly attracted to this as a food source and that the population is likely never high enough to break down the matter completely. This in my view warrents the use of siphoning, especially in the zones where there is low circulation and build up of detrius.

IME most of the critters cleaning the sand such as pods and bristle worms mainly come out at night and therefore is not affected to a large extent by the siphoning done during the day.

I also do not believe that there is a risk of depleting the bacteria population in the sand from siphoning. It may possibly lower the population and in theory reduce the nitrate reduction capacity of the sandbed for a period but the net effect of siphoning for me clearly wins over this possible reduction.

I also frequently turn up the sand inbetween siphoning/water changes to release detrius in the water column. This enables corals to feed on particles that would otherwise decompose in the sand. A portion is also given a second chance to be taken up by the skimmer. If you have not disurbed your sandbed for a long time I would not recommend this as it could risk releasing pockets of hydrogen sulfide into the water column.

Along with skimming, water changes and good water circulation I see siphoning of the sand as one of the best practices for ensuring a healthier and more successful reef.

 

[JoelA7]

Anyone have long term success with sugarfine DSB?

 

[Dog boy Dave]

anyone have long term success with sugarfine dsb?

yes

 

[JoelA7]

Hi Dog boy Dave. How long? Do you do any maintenance to it. Did you start with live sand or seed it?

 

[Randy Holmes-Farley]

I You barely even make a dent in the bacterial population on your skin when you take a shower, so how could siphoning your sandbed make the slightest difference to the bacterial population there?

While I'm not suggesting it is a big problem, I would point out that it is not nearly as simple as you suggest.

Bacteria in sediments are quite stratified, with different species living at different depths. Mixing the sand puts them in places they may no longer thrive/survive.

 

[Nano sapiens]

While I'm not suggesting it is a big problem, I would point out that it is not nearly as simple as you suggest.

Bacteria in sediments are quite stratified, with different species living at different depths. Mixing the sand puts them in places they may no longer thrive/survive.

In relation to bacteria responsible for nitrification and denitrification, fairly recent study on the subject has found that aerobic and anaerobic bacteria live in very close proximity to each other in what is termed a 'coupled' relationship. The anaerobes, not requiring oxygen, exist in the sand grains' micro pores while being surrounded by aerobic pore water utilized by the aerobic bacteria. This allows for simultaneous nitrifiction/denitrification (taken from Delbeek/Sprung 'The Reef Aquarium' pg 260, Jenkins and Kemp, 1984).

Even a shallow sand bed has the potential to effectively provide nitrification and denitrification. However, if the sand bed is clogged with detritus, the processes can't proceed efficiently due to lack of sufficient flow therein which is why I believe that some form of regular detritus export from the substrate(s) is very beneficial for a reef tank.

I am sure that stratification of bacteria of various types exist in a substrate, but I wonder how significant it is to keep them that way. Perhaps, this would be more important for a deeper sand bed system, but I am not sure.

 

[Randy Holmes-Farley]

Thanks.

I wasn't really addressing concerns about the nitrogen cycle not proceeding after vacuuming. I was addressing the simple assertion that vacuuming any sand bed couldn't reduce bacteria. I was just proposing a way that it could.

 

[Nano sapiens]

Thanks.

I wasn't really addressing concerns about the nitrogen cycle not proceeding after vacuuming. I was addressing the simple assertion that vacuuming any sand bed couldn't reduce bacteria. I was just proposing a way that it could.

Ah, I see. Looks like i read more into it than I should have

 

[Randy Holmes-Farley]

No problem. Other folks may have read it that way so the clarification is good!

 

[69bird]

Correct me if I am wrong, but doesn't Chingchai just rake his sand bed. We can all agree he has a beautiful tank. If raking the sandbed stirs up the detritus so that our filter systems can remove it, would that be " good enough".

 

[asylumdown]

I don't vacuum my sand as I do water changes out of my sump, but in the fall I started having a problem with cyano on the sand bed in certain places, and it would always come back in the same spots even after siphoning the entire patch and a few mm of the sand beneath it out.

I wondered if the sand in those spots had trapped enough detritus or nutrients that the cyano so able to harvest directly, as my nutrient tests kept showing undetectable levels of N and P. Since I didn't have a proper sand vacuum, I started fluidizing the sand in my tank using a turkey baster in patches. Even just doing it in a couple spots made it look like I'd dumped a whole bottle of coral snow in the tank. I'd have to change my filter socks several times over the next few hours, and my skimmer would go nuts for a bit, and as the water cleared I'd keep turkey bastering the rocks to make sure nothing settled on them.

I did that a couple of time a week for a month until I had 'fluidized' every inch of my sand bed (that I could reach) at least three times. While I've continued to have issues with cyano on an off in the months since, it's never come back on the sand bed.

Take that for what it's worth, and it's not something I'd recommend to someone else, but it's about the same as vacuuming. I couldn't believe how much gunk that was not sand got released in to the water in that process. By the third pass significantly less crap would come out, but something would always be liberated.

 

[Capn_Crunch]

From what I understand, the phosphate tests measure the organic phosphate levels, not the inorganic phosphate levels. The stuff you're vacuuming up is inorganic phosphate and will not show up during testing. Organic Phosphate will become inorganic phosphate over time which is one of the reason we strive to keep it as low as possible. Vacuuming the inorganic phosphate out of the tank will keep cyano blooms for occurring as well as other nasty things.

 

[Randy Holmes-Farley]

From what I understand, the phosphate tests measure the organic phosphate levels, not the inorganic phosphate levels.

No. All normal hobby tests measure only inorganic phosphate.

A very few tests have extra steps involving heating and/or digestion steps (of which Hach may be the only available kit, at least that I know of) that allow measurement of organic P.

 

[1fishkeeper]

I don't vacuum my sand bed but I will stir it and hold my hose above it to suck out all of the crud that moved up into the water when I do a water change.

 

[CoryD]

I have had this idea of some type of a sand bed stirrer. Something like a under gravel filter ran in reverse, in which water would be pumped under the sand and forced up. Kinda like a gfo reactor, in hopes that this would prevent detritus from settling into the sand bed. Has anyone tried anything like this? Is it a stupid idea? Anyway it could work?

 

[Nano sapiens]

I have had this idea of some type of a sand bed stirrer. Something like a under gravel filter ran in reverse, in which water would be pumped under the sand and forced up. Kinda like a gfo reactor, in hopes that this would prevent detritus from settling into the sand bed. Has anyone tried anything like this? Is it a stupid idea? Anyway it could work?

Not a silly idea, at all. It's called a RUGL (Reverse Under Gravel Filter), but has fallen out of favor. I remember these way back in the day...

 

[JoelA7]

I had a reverse flow 65 in the mid 90's. Quite good success for about 5-6 years then broke it down when we moved and only could keep my 150. Lotta gunk underneath the gravel in the void space. Corals did well. Fish did great.

 

[Slammed01]

Great thread, I removed some sand and got nasty water tonight from vacuuming the sand. Think it might be related to my algae fuzz!

 

[islandman41]

My tank was up and running good for around two years, I was having a great time with my tank, buying cool fish and some nice corals. Feeding them and keeping up with everything and doing a 30 gallon water change every two to three weeks. So at about the two year mark when I saw a little sign of GHA show up and then over about six months I watched it spread like a plague. I was like okay what now. It went from GHA to some nasty brownish red rusty looking junk that would slowly cover my sand then move its way over all my rock and coral. If I gave it much time with out trying to clean it off it would cover and start to kill everything. After over a year of trying every trick under the sun and reading for days on end then asking and showing every one I could, that also had no new advice or answers for me, well I found myself about to give up and sell everything. I had it all for sale and was slowly selling of my corals one at a time. Then my wife told me that if my system went out the door another one was not coming back in the house. So I went back to doing more research and found a thread about AlgaeFix, I started treating my tank with it, in a few treatments I could tell it was working. Along with me using my handy dandy toothbrush to scrub all the rock I was slowly getting things under control, but still the nasty brown stuff would not go away. So I went to searching the net again and came across this great thread and discussion about the deep cleaning of sand beds. I was like what the heck, done everthing else why not give it a try. So three weeks ago I got at it, siphoning every inch of my sand and blowing all my rock out with a power head and turkey baster.Talk about a storm in a tank, well I had a hurricane going on. Couldn't see anything in it at all. My sand was about three inches deep, so I also took it down to about 1"1/2. The nasty greenish, grayish, brownish gunk that I got out of my tank was a big eye opener for me. So it's been about three weeks and two siphonings since. WOW what a difference, no more nasty brown stuff growing across my sand and covering my rock work. After a year of trying and fighting with my tank, all it took was for me to siphone my sand bed. Thanks for the best advice I've ever come across since starting in this hobby.... It works and so far all my fish and corals are doing great. I will probably slap the next person that I hear telling someone to never clean their sand bed. Wish I could get all my money back that I've spent on GFO and then paid for the hours spent reading trying to find a cure. $$$ Siphon your sand people, it make a big diferance.

 

[Nano sapiens]

It works and so far all my fish and corals are doing great. I will probably slap the next person that I hear telling someone to never clean their sand bed. Wish I could get all my money back that I've spent on GFO and then paid for the hours spent reading trying to find a cure. $$$ Siphon your sand people, it make a big diferance.

Keeping a clean sandbed is one of the most often overlooked and often under appreciated processes for long-term success, IMO.

In my naturally filtered tank, I can control the nitrate and phosphate levels simply by increasing or decreasing the frequency of water changes/vacuuming to remove detritus (all other parameters staying constant).