Silicates???

[Mark75]

My 6 month old SPS dominate tank is experiencing a brown fuzzy growth (diatoms?) after a 10% water change. The tank is low nutrient, phosphate .03/nitrate 2 so I am suspecting silicates.

I use a BRS RO/DI unit with new filters, inline TDS meter reads 0. Could this be silicates? How well are they removed by a standard RO/DI unit and will the meter still read "0".

The only other culprit I can think of is my mixing tub, it is a clear plastic tote with folding lids, but o have used it for years surely it would not still be leaching?

Thanks for your help. [emoji3]

 

[brandon429]

an initially unrinsed sandbed is the greatest source of silicates I know

did you use live sand w no pre rinse

in time if that's the source, biofilms and other isolations/exports and bindings can occur to lessen avail, but that initial rinse is really critical to offset that potential source imo. good thing we can rinse live sand and not kill the bac.

 

[Mark75]

an initially unrinsed sandbed is the greatest source of silicates I know

did you use live sand w no pre rinse

in time if that's the source, biofilms and other isolations/exports and bindings can occur to lessen avail, but that initial rinse is really critical to offset that potential source imo.

Yes I did but that does not explain it only showing up immediately following a water change.

 

[brandon429]

I was thinking that upwelling any leftover silt might cause that type of kick up as water is poured in or removed, also, in some of the persistent diatom threads we didn't find Si to be the cause unless tested it was sandbed design issues and bright white lighting (such that things reversed when those were addressed)

I know your sps has light spec requirements and whites may be as required...but we get nice diatom fixes in changing to more blues where possible. your sourcewater sure could be a cause was just brainstorming alternates

can you post a full tank shot am curious how the bed looks

id be curious to know how your bed passes the little test where you reach in a corner, pick up a little sand, and drop it back down/ does it cloud massively

my grains on a six inch deep sand bed fall back down like snow globe grains totally clean... this helps to at least check possible sandbed locus

lighting adjustment sure worked great in other persistent diatom threads

you can find endless debating on brand names of salt sand etc causing this

 

[Sabellafella]

Yes I did but that does not explain it only showing up immediately following a water change.

What kinda salt you use

 

[Mark75]

Reef Crystals salt,..my sand bed is very thin,..less than a half inch in most places. It does cloud the water when disturbed.

 

[Randy Holmes-Farley Verified Community Expert]

Silicate isn't a "cause" of diatoms. It is one of many things they need.

Other things they need include a source of nitrogen (such as from some organics or ammonia or nitrate), phosphate, iron, and many other trace elements.

If any of these are currently limiting growth, then a water change that contained them or otherwise caused them to increase could be responsible.

 

[Mark75]

 

[brandon429]

that is a fantastic tank w zero problems

not having the selected grazers also matters, but then again I can only see awesomeness not lack of anything

I still think punchy white light on bright white sand matters. all substrates given enough maturation on the reef develop excluding communities that compete well. if your tank was mine id ensure no sourcewater addition and simply hand guide them out with water changes it should subside in time

 

[Sabellafella]

Reef Crystals salt,..my sand bed is very thin,..less than a half inch in most places. It does cloud the water when disturbed.

Reason i asked is i just ran into this same problem with a new box of rc. Found brown rocks in all the bags so maybe it has to do with organics

 

[Mark75]

I am running a hydra 52 blues at 100% whites at 40%,...is that to much white??

 

[brandon429]

the only way I could tell is to drop them to bluer and see. had to sustain mine a couple weeks to notice less diatom growback

I did this w my kessils and my sps are fine and the visual shift is bluer but they didn't care. I too had a bit of diatom cleaning on the glass and that's subsided bigtime, to me the lighting is the easiest to tweak and then put back if it didn't work. we are finding whites as a causative here in many cases.

as with any form of algae or invader control, the changes we make to the tank shouldn't be intended to both remove and prevent the target at hand, that's the common way.

the uncommon way is to hand clean the entire tank of the invader, then make changes as only growback prevention. that alone is a major fix technique for sure.

 

[Mark75]

What are the chances this will go away as the tank matures? The tank is still young,..6 months,..I do not want to make a bunch of changes for a temporary problem.

 

[brandon429]

that's totally variable honestly. you have some threads with persistent Dinos for literally 3 years and they tried every factor but sandbed compliance cleaning... its understandable about you wanting to weigh options, id simply blue up the lights a bit and hand remove light siphon the top layers out and repeat as needed 4 weeks, these are very nonimpactful options to try. if no lessen whatsoever in a mo, next level is avail.

additionally, UV is indicated here as diatoms have a pelagic phase and can be intercepted and burned like bad popcorn during their diurnal runs. UV is a fine cheat that can be reduced or stopped whenev, then plugged in to cheat etc I love them and your invader can be zapped by a correctly sized one for sure. I guarantee if I owned a large tank id have a pond sterilizer on hand in the closet for big cheats, it can be the swingvote in sooooo many different invasions (pelagic floaters not benthic anchored invaders)