Established tank with diatoms on sand, why?

[Fisherman Joe]

Hi all.

Has anyone had a well established tank suddenly have diatoms come back on the sand?

I think it’s due to my silicates. They are around 400 or so on an ICP test, as far as I recall they we’re higher than the green bar, slightly red.

I’ve ordered a new membrane for my RO unit.

I have plenty of cleanup crew but I still get brown sand during the day.

Any tips?

 

[Reefer Matt]

Diatoms will show up with high silicates. Silicates are what they eat. However, I would be sure it is diatoms and not cyano or dino. Diatoms will go away after the silicates go down, dino and cyano require intervention.

 

[Fisherman Joe]

Good point.
How do you tell the difference again please?

 

[Reefer Matt]

Good point.
How do you tell the difference again please?

Visually, diatoms are brown and powdery. Cyano and dino are similar, but dino form a long, bubbly, snot looking mass. Cyano is red or green usually, and makes a bubbly mat. A microscope is the best way to tell.

 

[Timfish]

Yup. Reef systems are dynamic and even in tightly monitored systems the microbial stuff is in constant flux. This paper is an excellent example: Microbiome Dynamics

Over the decades I've kept systems I've learned to expect stuff to show up from time to time, it might be seasonal, it might be years but sooner or later stuff shows up. FWIW I only use mechanical removal for nuisance stuff growing on sand. SOjmetimes it's just gently siphoning it off, sometimes it's a gravel vacume, sometime it's using siphoning out a fair amount of sand and soaking it in H2O2 to kill it then rinsing well, letting dry and returning to a ssytem.

 

[Fisherman Joe]

Good tips. Thanks.

It’s defo diatoms

 

[Fisherman Joe]

Yup. Reef systems are dynamic and even in tightly monitored systems the microbial stuff is in constant flux. This paper is an excellent example: Microbiome Dynamics

Over the decades I've kept systems I've learned to expect stuff to show up from time to time, it might be seasonal, it might be years but sooner or later stuff shows up. FWIW I only use mechanical removal for nuisance stuff growing on sand. SOjmetimes it's just gently siphoning it off, sometimes it's a gravel vacume, sometime it's using siphoning out a fair amount of sand and soaking it in H2O2 to kill it then rinsing well, letting dry and returning to a ssytem.

That is an interesting paper!