Why does waiting out diatoms in a new tank work?

kartrsu

Well-Known Member
View Badges
Joined
Apr 20, 2019
Messages
701
Reaction score
535
Location
Glendale, CA
Rating - 0%
0   0   0
I am currently battling diatoms in my new 65G. The bloom has gotten ridiculously bad in the beginning but now is starting to come back less aggressively.

Today I cleaned my back wall. It was completely covered in hair algae and a very intense dusting of diatoms (confirmed under microscope). I was shocked at how thick the mats were when I scraped it off but eventually got 95% of it off.

I then had this thought. Diatoms feed off silicates and the advice for the new tank is to let it run its course until the silicates are consumed. However, if diatoms die off, don’t the silicates return back to the water assuming no water changes? Then the diatoms should return. Must be missing something here.

Anyway, it was super satisfying to clean the back wall and remove all this brown green gunk. If by doing manual removal also removes available silicates used by living diatoms, well atleast I’m going in the right direction.
 

Subsea

5000 Club Member
View Badges
Joined
Jun 21, 2018
Messages
5,332
Reaction score
7,664
Location
Austin, Tx
Rating - 0%
0   0   0
I am currently battling diatoms in my new 65G. The bloom has gotten ridiculously bad in the beginning but now is starting to come back less aggressively.

Today I cleaned my back wall. It was completely covered in hair algae and a very intense dusting of diatoms (confirmed under microscope). I was shocked at how thick the mats were when I scraped it off but eventually got 95% of it off.

I then had this thought. Diatoms feed off silicates and the advice for the new tank is to let it run its course until the silicates are consumed. However, if diatoms die off, don’t the silicates return back to the water assuming no water changes? Then the diatoms should return. Must be missing something here.

Anyway, it was super satisfying to clean the back wall and remove all this brown green gunk. If by doing manual removal also removes available silicates used by living diatoms, well atleast I’m going in the right direction.

Unless you provide a syphon to filter out what was scraped off, the nutrients are still tied up with floating micro algae mass. As other more desirable photosynthetic life forms grow in population, then competition & predation help establish homeostasis. Until those other populations develop, you are left with the uglies.
 

Auquanut

5000 Club Member
View Badges
Joined
Mar 11, 2018
Messages
5,275
Reaction score
24,934
Location
Mexico, Mo
Rating - 0%
0   0   0
I then had this thought. Diatoms feed off silicates and the advice for the new tank is to let it run its course until the silicates are consumed. However, if diatoms die off, don’t the silicates return back to the water assuming no water changes? Then the diatoms should return. Must be missing something here.
I'm assuming that as the diatoms die off or are consumed by the CUC, your filtration and tank maintenance remove the silicates with the diatoms/detritus over time. I'm thinking that if there are no water changes, the process would take longer.
 

taricha

5000 Club Member
View Badges
Joined
May 22, 2016
Messages
6,484
Reaction score
9,996
Rating - 0%
0   0   0
I then had this thought. Diatoms feed off silicates and the advice for the new tank is to let it run its course until the silicates are consumed. However, if diatoms die off, don’t the silicates return back to the water assuming no water changes? Then the diatoms should return. Must be missing something here.
Interesting Q.
Si is consumed quickly. By diatoms and by sponges, and maybe by other processes I don't know off the top of my head.
Here's other things that can happen. When diatoms (or sponge tissue) dies, then sponge spicules and diatom frustules (the skeletons of those) sit in the sand. This silica material is not re-released quickly. It might be re-released slowly.
Also diatoms can enter a resting state in the sand and remain there for some extended time without dying.
 
OP
OP
kartrsu

kartrsu

Well-Known Member
View Badges
Joined
Apr 20, 2019
Messages
701
Reaction score
535
Location
Glendale, CA
Rating - 0%
0   0   0
Very interesting thoughts! I pondered this because I recently did an ICP test on my new tank and one more mature. Surprisingly the one that was more mature had higher silicates in the water but no diatoms. The older tank does have more sponges under the rocks though, so maybe the diatoms are being out competed. Both tanks have minimal clean up crews.

I read or watched somewhere that because the diatom shell is rigid, the diatom can only reproduce by halfing. As that process continues it reaches a physical limitation, causing the die off. Not sure if that’s all diatoms but I thought that was interesting.

Nonetheless, I figured manual removal wouldn’t hurt. Before I’d blow it off the rocks and scrape the glass. Some would make it to the filter socks and skimmer but they largely came back. This time, I sucked it out with a water change and the resurgence is less vicious.
 

homer1475

Figuring out the hobby one coral at a time.
View Badges
Joined
Apr 24, 2018
Messages
11,677
Reaction score
18,662
Location
Way upstate NY
Rating - 0%
0   0   0
Sure your dealing with diatoms and not dinoflagelletes(dino's)?

From your description of them being in your sock, skimmer, glass, sandbed, etc, it almost sounds like dino's to me. Typically diatoms stay on the sandbed where the silicates are.
 
OP
OP
kartrsu

kartrsu

Well-Known Member
View Badges
Joined
Apr 20, 2019
Messages
701
Reaction score
535
Location
Glendale, CA
Rating - 0%
0   0   0
It’s a bit of both. I’ve microscoped samples from both my rocks and glass. The sand actually stays pretty white surprisingly. On the back glass, I had hair algae covered with diatoms. The rocks are graced with diatoms intermixed with small cell amphi dinos. I run UV, so the dinos are kept in check.
 

Madonia

Active Member
View Badges
Joined
Jan 9, 2020
Messages
393
Reaction score
271
Rating - 0%
0   0   0
I have the same problem. Now I decided to try out phosguard in replacement of running GFO. Trying to remove silicates. Assuming they are from dry rock used, as I have 0tds water
 

blasterman

Valuable Member
View Badges
Joined
Feb 14, 2019
Messages
1,730
Reaction score
2,018
Rating - 0%
0   0   0
I still get diatoms in 2yr old BB tanks.

I'm beginning to suspect its due to cheaper glass tanks feeding silicates, but can't prove it.
 
OP
OP
kartrsu

kartrsu

Well-Known Member
View Badges
Joined
Apr 20, 2019
Messages
701
Reaction score
535
Location
Glendale, CA
Rating - 0%
0   0   0
I have the same problem. Now I decided to try out phosguard in replacement of running GFO. Trying to remove silicates. Assuming they are from dry rock used, as I have 0tds water
Turns out I didn’t just have diatoms. The brown mess was mostly chrysophytes. I ran GFO to remove silicates and phosphates and dosed fluconazole with a 3 day blackout. That and manual removal knocked everything back. Does phosguard remove silicates?
 

Subsea

5000 Club Member
View Badges
Joined
Jun 21, 2018
Messages
5,332
Reaction score
7,664
Location
Austin, Tx
Rating - 0%
0   0   0
My mixed garden macro tank has ornamental sponges that I purchased but also some that grew off live rock. The water is this tank is saturated with silica but no diatoms. Competition for food & predator behavior from diversity of life forms might explain lack of diatoms.
 
Last edited:

Mastering the art of locking and unlocking water pathways: What type of valves do you have on your aquarium plumbing?

  • Ball valves.

    Votes: 71 53.0%
  • Gate valves.

    Votes: 68 50.7%
  • Check valves.

    Votes: 34 25.4%
  • None.

    Votes: 30 22.4%
  • Other.

    Votes: 9 6.7%

New Posts

Back
Top