Understanding diatom and Cyanobacteria during cycle

[newfly]

Trying to read up on the ugly phase. I’m still have a ways to go before getting the tank wet. Dry rock have been cycling in a tub and doing what it supposed to do.
I’m just trying to get a feel on what’s likely to happen next.

I understand diatom phase usually comes after cycle. Diatom feed on silicate. I assume light also play a role in diatom bloom?

In my case, I am starting off with RODI water (0tds) and bare bottom (no sand)

1. What’s the likely source of silicate in the water that feed diatom?

2. Do diatom feed of nutrients from fish food/waste?

In my case, since the rock is soaking in a tub, can I artificially trigger the diatom phase in the tub? What do I need? Fish food? Lights?

Similarly if someone can help me understand the cyno phase. What cause cyno bloom (I read cyno bacteria is everywhere) and if I can trigger this while cycling my rock in a tub.

 

[Spare time]

I believe that a lot of it comes from lack of biodiversity. Some tanks never get cyano issues, just as some don't get hair algae issues, etc.. Which pops up seems to be based on whatever gets their footing in.

Any silicate in the tank is quickly taken by diatoms (though not exclusively), and then I believe when it becomes limited their numbers crash.

Cyano is another thing that if there is little competition or predation, they can take off. They can also thrive with 0 nitrates as they can get their nitrogen from the atmosphere.


As rock ages in a tank, more things grow, eat, and compete on the surface.

 

[biophilia]

Soluble silica will still be present in your tank in the beginning evening without sand of any kind. Most will probably come from your salt mix itself (most salt mixes have silicate levels similar to that of the ocean (say 1-5ppm). A tiny bit may get added from food.

In the beginning your rock won't have the sponge growth or diatom-consuming herbivores in it to consume that silicate very quickly so the bloom is really inevitable. It does need light, so putting lights over your tub will help, along with a source of nitrogen and phosphorus. That will probably come naturally from the cycling process (whichever way you go about it) but adding a little fish food if you're only cycling by adding ammonia might help the process a bit...

 

[newfly]

How do I increase biodiversity from a dry rock? Or naturally it will happen from the bacteria around us.

 

[biophilia]

Siliceous sponges and animals that rapidly eat diatoms, like copepods, will hitchhike in on coral frag or even in the water that makes its way in along with the fish. That being said, you can dramatically increase that biodiversity by getting some rock or sand rubble from local reefers, buy and add live copepods from places like Algae Barn, or getting one of the biodiversity kits from Indo-Pacific Sea Farms. Just buying a single coral attached to a piece of live rock is all you really need to do.

 

[Spare time]

How do I increase biodiversity from a dry rock? Or naturally it will happen from the bacteria around us.

You can add things like PNS probio, dr tims waste away gel (this worked well for a guy who shops at the lfs I work part time at) and eco balance, microbacter 7 (a mix of these and nitrifyers), reef brite live rock enhance, macroalgaes (you can add decorative ones), live phytoplankton, etc.. Just make sure to stay above 0 for nitrate and phosphate, but not super high for phosphate (a little above 0 is perfect, such as 0.03-0.1). Live rock can help but can bring numerous things you don't want.

 

[A2dahlberg]

I too am having the same thing happen with Diatoms. Spreads really fast under my stock Evo 13.5 light. It didn't start until I put in a cycled rock from a not to LFS. I do have a emerald crab on the way to help.

 

[Jekyl]

Uglies are just part of the process. The bacteria and coraline you want are the tortoise and gha, diatoms etc are the hare. If already cycling your rocks and dosing ammonia as you go you're speeding both animals up. Hare will still have the lead.

 

[PghReef]

Diatoms are nothing to worry about or try to get ahead of in my experience. They come fast and die off even faster. A tank needs time to stabilize. Microfuana populations will grow, micro algaes and coralline algae will proliferate and compete with the bad algaes. Depending how you set up your tank determines how fast this happens.

Getting ahead of cyano, gha, dinos is what you focus on to prevent headaches. Limit light cycles, stock slowly, use a good CUC and utility fish, do not EVER let nutrients bottom out, and don't have any knee jerk reactions.

The quickest way to help all this happen is with good quality liverock. Makes a night and day difference in my opinion.