Film on rock work??

[jmdall]

Hi everyone

I have been working my way through a diatom issue (I think I have this under control) but recently noticed when blowing rock work off in one section of tank that there is a whitish film on the rock surface under the diatoms

Tank is 8 months old…

Water chem is good (too clean in fact = diatoms), RODI, monitor daily, most corals look great but some have been less impressive coinciding with diatoms out break - also noticed recently some Trochus snails acting lethargic, in some cases moving very little each day and my Tomini tang pecks at the rock work less it seams (whiteish algae?)

I tried taking pictures below - any thoughts or ideas?

Thanks in advance

 

[vetteguy53081]

Hi everyone

I have been working my way through a diatom issue (I think I have this under control) but recently noticed when blowing rock work off in one section of tank that there is a whitish film on the rock surface under the diatoms

Tank is 8 months old…

Water chem is good (too clean in fact = diatoms), RODI, monitor daily, most corals look great but some have been less impressive coinciding with diatoms out break - also noticed recently some Trochus snails acting lethargic, in some cases moving very little each day and my Tomini tang pecks at the rock work less it seams (whiteish algae?)

I tried taking pictures below - any thoughts or ideas?

Thanks in advance

These are diatoms and are a brown algae that typically appear in a tank which has just completed its cycle but they can also appear in an established reef tank and looks ugly but in most cases are harmless and feed mainly off of silicates as well as dissolved organic compounds, phosphate and nitrates. Tap water can contain silicates and is a good way to get a bloom if you use it to mix salt or to replace water that evaporated from the tank. Using an RODI unit helps, although you can still get diatoms with an RODI unit if the cartridge that removes silicates becomes expired.
Diatoms are typically harmless and can be beaten once their food source is gone.
For major outbreaks you may want to consider a three day blackout. They are easily wiped from the glass with a mag float, a turkey baster or a toothbrush can cover other areas of the tank. Be prepared for them to re-establish themselves quickly after a cleaning as they are likely to be able to reappear and have re-growth rates.
To prevent their return, do regular water changes, keep the bedding clean, don’t overfeed tank, ensure your skimmer is running at an optimal level and keep filter socks and sponges clean on a regular basis.
Some cleaner crew to help control it are : Cerith snails, Nerite snails and Trochus snails and also Astraea snails are effective at removing diatoms.

 

[Uncle99]

“Too clean” can bring many pest type algae’s and bacteria’s not just diatoms.

Looks golden in the pics but maybe just the light.

Do they come off the sand at night, then return when lights on, or just stay put?

What are the parameters and length of time rock solid stable?

 

[jmdall]

“Too clean” can bring many pest type algae’s and bacteria’s not just diatoms.

Looks golden in the pics but maybe just the light.

Do they come off the sand at night, then return when lights on, or just stay put?

What are the parameters and length of time rock solid stable?

Thanks

Yes for the photo I turned the white light and intensity way up, otherwise the pics look very blue and tough to make anything out with my poor photo skills

My understanding was the Dino’s are the brown, fragile population, easily disturbed and removed from the rock and substrate surface - what I am seeing below the brown algae, only in some areas of the rock work, appears white or light gray and does not blow away but perhaps they are related

Parameters have been pretty stable all along - I have been trying to stay on top of things - nitrates got as high as 10ppm and phosphates as high as 3ppm a few months ago but I was able to get that corrected pretty quick
Temp 78
Salt 1.025
ORP 350
pH 8.3
NO3 0.0
PO4 0.03
Alk/Calcium/Mag stable and in range

Everything stays put - the algae doesn’t seem to migrate between lights on/off I think but I’ll try to watch more closely

 

[jmdall]

These are diatoms and are a brown algae that typically appear in a tank which has just completed its cycle but they can also appear in an established reef tank and looks ugly but in most cases are harmless and feed mainly off of silicates as well as dissolved organic compounds, phosphate and nitrates. Tap water can contain silicates and is a good way to get a bloom if you use it to mix salt or to replace water that evaporated from the tank. Using an RODI unit helps, although you can still get diatoms with an RODI unit if the cartridge that removes silicates becomes expired.
Diatoms are typically harmless and can be beaten once their food source is gone.
For major outbreaks you may want to consider a three day blackout. They are easily wiped from the glass with a mag float, a turkey baster or a toothbrush can cover other areas of the tank. Be prepared for them to re-establish themselves quickly after a cleaning as they are likely to be able to reappear and have re-growth rates.
To prevent their return, do regular water changes, keep the bedding clean, don’t overfeed tank, ensure your skimmer is running at an optimal level and keep filter socks and sponges clean on a regular basis.
Some cleaner crew to help control it are : Cerith snails, Nerite snails and Trochus snails and also Astraea snails are effective at removing diatoms.

Thanks for the reply - is it common to see a whitish base layer below the brown, more fragile and easily disrupted top layer of algae

I will try to get a sample, I work in a lab with lots of scopes available

 

[vetteguy53081]

Thanks for the reply - is it common to see a whitish base layer below the brown, more fragile and easily disrupted top layer of algae

I will try to get a sample, I work in a lab with lots of scopes available

yes, from silicates and detritus

 

[Uncle99]

Thanks for the reply - is it common to see a whitish base layer below the brown, more fragile and easily disrupted top layer of algae

I will try to get a sample, I work in a lab with lots of scopes available

You level and idea of stability and mine may be wide apart, without posting, not going to comment on those and they can have a huge impact on chemistry and those who live in it.

Nitrate and phosphate are zero and could be zero which means your system favours pest type stuff like your seeing. I’d bump them into range so your system will mature up with good guy stuff.

The film like that is common and is another sign that chemistry may not be in check. The pest algae may feed off that as well.

The good news is that stuff is easier to fix.

Check Alk daily. It should not flux more than .1 dkh at any time. That’s not hard to achieve.

Check MG is somewhere between 1350-1400ppm.
Too high of MG can slow snails.

Bump nitrate up to say 5ppm and phosphate to .1ppm so we can feed the system encouraging the growth of good guy algae’s and bavterias.

These are the guys that keep rocks clean and sand white.