Diatom bloom? Mature tank! Advice needed.

[vwjunkie]

Hi. I havent posted for a while but am in need of some help, or at least advice, on what to do and what is causing this problem I have.
My tank is about 18 months old , give or take a week or two. When I say mature, I mean the rock and sand is. I recently changed tanks so transferred all rock, sand and inhabitants over to my new tank, a Red Sea Reefer 170.
All has been well for the last couple of months since the move but over the last few days it has been hit with this awful brown bloom, covering everything...glass, rock. sand, corals,powerheads and even my snails are starting to look brown.
I have tested for Nitrate, Nitrite, Phosphate and Ammonia trying to figure out whats going on but all are at zero except for nitrate which is at 5-10ppm.
The only thing of note that has happened recently is my sand sifting Goby has gone missing and the problem seems to have started since then.....

Can anyone shed any light on what they think the problem is?

Salinity always at 1.025/1.026
Always 0TDS RO/DI water used for ATU and salt water prep.
Temp hovers around 25/26c
Deltec Skimmer
Rowaphos reactorm media changed roughly every 4 weeks.

Fairly lightly stocked, 2 clowns, 2 small Gobies, 2 cleaner shrimp, 2 emerald crabs and CUC snails
1 Daisy colony
1 small torch frag
1 small maze
1 small plate
1 small GSP rock
All were doing well before this outbreak but they arent looking so good at the minute.

LED light comes on 9 am and ramps up slowly over a couple of hours to about 75% power on whites and 80% blues til about 6pm when it ramps down to about 40% blue then switches off at midnight

Regular bi weekly 15% water changes but I have done 15% every couple of days for the last week and the problem persists......I blew off most of the brown stuff from the sand and rocks with a turkey baster and scraped the glass before the last water change and it looked improved but the next morning was almost back to the way it was.

Should I be worried? Will it pass and if not what can I do to get rid of it......what have/ am I doing wrong
Any help greatly appreciated
Cheers

 

[Phil077]

To much silicates/nitrates/poor lighting/low oxygen levels will cause diatom blooms and cyanobactaria
Also over feeding would be a problem

 

[vwjunkie]

To much silicates/nitrates/poor lighting/low oxygen levels will cause diatom blooms and cyanobactaria
Also over feeding would be a problem

Thanks for replying. Nitrates are OK, 5-10 ppm. Not sure about silicates or exactly what they are. What would be poor lighting? The light I use is TMC iLuminaire 600 and corals were doing fine up til this week. I usually only feed frozen food sparingly.....although, having said that, our freezer packed in a fortnight ago and we have only just managed to replace it this weekend so have been feeding Vitalis marine pellets in the meantime.......
Am I right in thinking the Sand siftiing Goby is perished, as I havent seen hime for weeks.....and if so wouldnt his remains have been scavenged? If this was a problem surely Amm and Nitrite would have went up.....but they are zero?
Would leaving the lights off for a day or two be a possible solution, or would this cause more harm than good?
Cheers.

 

[cuprajake]

silicates in sand.

did u clean your old sand. or use fresh

 

[Phil077]

Thanks for replying. Nitrates are OK, 5-10 ppm. Not sure about silicates or exactly what they are. What would be poor lighting? The light I use is TMC iLuminaire 600 and corals were doing fine up til this week. I usually only feed frozen food sparingly.....although, having said that, our freezer packed in a fortnight ago and we have only just managed to replace it this weekend so have been feeding Vitalis marine pellets in the meantime.......
Am I right in thinking the Sand siftiing Goby is perished, as I havent seen hime for weeks.....and if so wouldnt his remains have been scavenged? If this was a problem surely Amm and Nitrite would have went up.....but they are zero?
Would leaving the lights off for a day or two be a possible solution, or would this cause more harm than good?
Cheers.

I Have lost bigger fish in my tank, never to be seen again. a good mature tank will break them down sometimes without a spike in parems
Turning your lights off wont do anything imo brown algae are autotrophic and produce there own food
Increase waterflow if you can, are you using a good salt brand? is your r/o water readings ok?

 

[372xp]

Rowa phos removes silicates. And you change this every 4 weeks. More than likely caused by a +/- shift in nutrient balance.

 

[vwjunkie]

Ah. I used some old sand and also put some new stuff in there, probably half and half. I have increased the flow and placed my powerheads in different places to try and increase movement through the rock and over sand without disturbing it.
Am also upping blues and lowering whites on daylight setting on the light.
What method do you guys use to balance nutrients....I thought I had it OK with 0 Phosphates and 5-10 nitrates. Alk is round the 10 mark, Ca 420-450, Mg seems to stay high at around 1500.
Was using Polyplab One but it didn't seem to keep things balanced and Mg has stayed high since stopping a few weeks ago.....now manually dose separate Alk, and Ca every couple of days til I get a dosing pump.
Cheers

 

[Phil077]

Ah. I used some old sand and also put some new stuff in there, probably half and half. I have increased the flow and placed my powerboats in different places to try and increase movement through the rock and over sand without disturbing it.
Am also upping blues and lowering whites on daylight setting on the light.
What method do you guys use to balance nutrients....I thought I had it OK with 0 Phosphates and 5-10 nitrates. Alk is round the 10 mark, Ca 420-450, Mg seems to stay high at around 1500.
Was using Polyplab One but it didn't seem to keep things balanced and Mg has stayed high since stopping a few weeks ago.....now manually dose separate Alk, and Ca every couple of days til I get a dosing pump.
Cheers

Then That could of been your problem then, your parems seem ok imo

 

[vwjunkie]

Thanks folks. Will give it a few days to see if the bloom passes. Hopefully the small changes I've made to flow and lighting will help.
Cheers