Never ending sandbed diatoms

[Dodger745]

I have an established 180g reef. I use a BRS 5 stage ro/DI unit. I change 25 gallons every two weeks.
I have a 40 gallon sump with an aqua c ev 240 skimmer. Running halides, calcium reactor, carbon and phosguard.
My corals are happy, fish doing great, only thing I have going on is diatoms that will never go away in my shallow sandbed.

Any ideas?!

[Reefmedic79]

They are just part of a tank, IMO. Increasing flow along the sand bed and having sand shifting organisms, i.e. nassarius and/or snails, can help prevent it from proliferating.

[IslandCrow]

Please define never ending. How long has your tank been set up, and how long have you had an issue with diatoms? It may just be normal, or it may be indicative of another issue.

[Dodger745]

I can move the sand around with a toms aquatic sand take, and within a few hours the brown mess starts to re-appear. It's only in the sandbed. I have a good variety of snails in my tank from reef cleaners. I am thinking of adding a diamond goby

[Dodger745]

My tank has been going for about 9 months at my house. It was an established system that I purchased as a complete running setup and had been going for over 5 years when I bought it

[Kdawg_69]

just get a couple sand sifting blennys and call it a day we have got to get another after ours died going into a qt tank after a couple fish got ich

[IslandCrow]

Have diatoms been an issue the entire 9 months, or is it more recent than that? Also, do you know if it was an issue over the previous 5 years? Right now, I'm a little bit at a loss. I did have an incident or two when my tank had been set up for over a year where I'd get diatom blooms on my sand for a few months. I was extra vigilant on the water changes, and that seemed to be all it took for it to eventually subside. Diatoms are not necessarily a horrible thing, but it definitely is unsightly. Afraid I can't think of much else that you're not already doing, though.

[njudson]

silica based sand?

[greech]

Had the same problem for almost a year. Added a fleet of small fighting conchs and started running Rowaphos in my reactor. No diatoms for 3+ years now.

[Psyops]

Originally Posted by greech

Had the same problem for almost a year. Added a fleet of small fighting conchs and started running Rowaphos in my reactor. No diatoms for 3+ years now.

That's basically what I did also. Instead of Rowaphos I used GFO from BRS. Conchs are great and cool to watch.

I would probably increase the water change routine to weekly. I had the same issue when I was doing 2 week water changes. No issues for 2 yrs now on weekly change routine. Hope this helps.

Alex

[ivar85]

PhosGuard did the trick for me : )

[vitz]

Originally Posted by Dodger745

I have an established 180g reef. I use a BRS 5 stage ro/DI unit. I change 25 gallons every two weeks.
I have a 40 gallon sump with an aqua c ev 240 skimmer. Running halides, calcium reactor, carbon and phosguard.
My corals are happy, fish doing great, only thing I have going on is diatoms that will never go away in my shallow sandbed.

Any ideas?!

you'll need to change quite abit more than 25 gallons to have any kind of impact on removing pollutants from the water column.

if the goal is to remove pollutants by dilution via a water change, efficiently and quickly, you're looking at 40-50% wc's at a minimum

[Dodger745]

Ive never heard of doing routine 50% water changes with saltwater aquaria. Just sayin

[vitz]

Originally Posted by Dodger745

Ive never heard of doing routine 50% water changes with saltwater aquaria. Just sayin

i and many others have been doing 50-90% wc's for years and years. my healthiest most productive tank was a 75 that had an 80-90% wc done weekly/every other week. it's simple math-anything less than 50% isn't really worth doing, if fast and actual removal of organics buildup is the goal-this article explains it very well

http://www.reefs.org/library/article...htbill_wc.html

[Touring]

Sandbeds FTL......

[Dodger745]

How much money per month would you estimate you were spending on salt mix? I couldn't imagine doing a 50 percent change every week in my 180.

[vitz]

so do it once/month. one 50% water change does far more removal/replenish than 5x 10% does

[Duvallj]

Originally Posted by vitz

so do it once/month. one 50% water change does far more removal/replenish than 5x 10% does

More, yes, far more, not really.
http://www.reefkeeping.com/issues/2005-10/rhf/

Then other things come in practically. You can siphon a sandbed 5 times doing 10% rather than the once doing a 50%. Well you could do just sandbed cleaning, but its just more practical doing at the same time.
Also you introduce the possibility of shock/stress into the system by doing large water changes compared to smaller ones. Yes a 50% will remove pollutants quickly, but is it needed in this case? Unless there is an emergency or something else more stressful than a large water change I would opt for smaller ones.

Of course there are many thoughts on this and you certainly can do large or small water changes.

As for dodger's water change regiment, your probably close to 30% monthly, I predict just under (using actual system volume estimates). The true story will be told in what our phosphate/nitrate/possibly silicate levels are. Even then some pest just seem to want to hang on even in low nutrient systems.

I'd aim for more sand shifting critters. Even if they don't directly eat it, just the turning of the sand as the forge can be enough to keep the mats of crud in check. You'll probably have to feed most of these critters adding more nutrients into the system however from the sound of things this probably is a non-issue.

Adding more water flow at the sand bed will help as well. The trick is just enough to keep debris from settling, but not enough to move your sand about. Really it just takes tweaking to get this part right.

[Fragtastic Reef]

What do you have for flow in the tank I do not see it mentioned? I would recommend more flow first and WC's and cleaning the sandbed.

[vitz]

Originally Posted by njudson

silica based sand?

there's an article in either the RK or AAOLM archives on the subject of silica sand. it doesn't leach silicates or feed diatoms. pretty much remains inert, iirc.

[Dodger745]

I'm thinking of trying ways to increase flow near the sandbed. I have dual overflows to my sump, and I run a fairly large dolphin return pump. I have two return lines that are split to make 4 diff loc lines. I have them pointed in all diff directions. But I could probably benefit from a set of wave making power heads I'm sure.

[IslandCrow]

Originally Posted by vitz

there's an article in either the RK or AAOLM archives on the subject of silica sand. it doesn't leach silicates or feed diatoms. pretty much remains inert, iirc.

There are theories that the crystalin structure of the sand may be a factor in providing a more conducive surface to the growth of diatoms. I don't think I've ever seen any actual evidence to support that, though.