Dino questions

[CatsandClowns]

Heyo,
I was hoping I wouldn't join the club but I think Ive gotten dinoflagellates. I do not have a microscope so Ive compared the appearance of mine with others ive seen. I dont have much space for extra equipment nor do I want to throw the kitchen sink at it trying to solve this. Granted it has gotten less noticeable as of lately I just want to get some clarity on nitrate dosing when it comes to dealing with dinoflagellates. Generally people recommend dosing nitrates to promote the growth of other more favorable algae(anythings aside from bryopsis is better which unfortunately I might also have) since dinos are more efficient at growing at lower nutrient concentrations than others. However Im also led to believe this will just lead to a 'dino' bloom.
Is this bound to occur before it decreases in quantity. For reference my most recent testing showed ~0.2ppm NO3 and 0.09ppm PO4. While they are predominantly on the sandbed, it does seem to have visually decreased in concentration since Ive diminished feeding volume a bit over a week ago. Aside from that I intend on not doing a water change at least for this week alone to let the tank stabilize and work itself out without my grubby paws in there trying to "clean" it.
Despite sorting through a bunch of nitrate dosing threads, it does seem a bit counterproductive at this moment, could anybody clarify or attest to any affects causing by nitrate dosing when risking a dino bloom. Let me know if you need further information, thanks!

 

[Rocks reef]

I would start by increasing your NO3. Since your PO4 is 0.09, I'd raise my NO3 to at least 10, maybe even as high as 15.
How is your water flow?

 

[Subsea]

….consider dosing silicates to feed diatoms that outcompete Dinoflagellets & Cyanobacteria. Everybody eats diatoms.

 

[CatsandClowns]

I would start by increasing your NO3. Since your PO4 is 0.09, I'd raise my NO3 to at least 10, maybe even as high as 15.
How is your water flow?

Would you recommend dosing 1ppm all at once multiple times throughout the day. Also since the evaporation is often inconsistent would it be more effective to just dilute 1ppm nitrate in a liter of tank water then place back in rather than relying on auto top off, also does it need to be diluted in RODI?

 

[CatsandClowns]

….consider dosing silicates to feed diatoms that outcompete Dinoflagellets & Cyanobacteria. Everybody eats diatoms.

Do you use the brightwell stuff?

 

[Subsea]

Do you use the brightwell stuff?

No.

My ground water at 1000’ comes from the Middle Trinity which used to be an ancient inland sea which was full of diatoms. Because I favor ornamental & cryptic sponges, I use this source of makeup water to feed trace minerals to reef tanks as TDS is 950 ppm.

 

[CatsandClowns]

No.

My ground water at 1000’ comes from the Middle Trinity which used to be an ancient inland sea which was full of diatoms. Because I favor ornamental & cryptic sponges, I use this source of makeup water to feed trace minerals to reef tanks as TDS is 950 ppm.

Ah, well ive got that hard garbage water in SoCal. Ill look into alternatives

 

[CatsandClowns]

Would you recommend dosing 1ppm all at once multiple times throughout the day. Also since the evaporation is often inconsistent would it be more effective to just dilute 1ppm nitrate in a liter of tank water then place back in rather than relying on auto top off, also does it need to be diluted in RODI?

Ignore this, was dumb question,

 

[vetteguy53081]

Heyo,
I was hoping I wouldn't join the club but I think Ive gotten dinoflagellates. I do not have a microscope so Ive compared the appearance of mine with others ive seen. I dont have much space for extra equipment nor do I want to throw the kitchen sink at it trying to solve this. Granted it has gotten less noticeable as of lately I just want to get some clarity on nitrate dosing when it comes to dealing with dinoflagellates. Generally people recommend dosing nitrates to promote the growth of other more favorable algae(anythings aside from bryopsis is better which unfortunately I might also have) since dinos are more efficient at growing at lower nutrient concentrations than others. However Im also led to believe this will just lead to a 'dino' bloom.
Is this bound to occur before it decreases in quantity. For reference my most recent testing showed ~0.2ppm NO3 and 0.09ppm PO4. While they are predominantly on the sandbed, it does seem to have visually decreased in concentration since Ive diminished feeding volume a bit over a week ago. Aside from that I intend on not doing a water change at least for this week alone to let the tank stabilize and work itself out without my grubby paws in there trying to "clean" it.
Despite sorting through a bunch of nitrate dosing threads, it does seem a bit counterproductive at this moment, could anybody clarify or attest to any affects causing by nitrate dosing when risking a dino bloom. Let me know if you need further information, thanks!

I wouldnt up front dose nitrates as when we see zero readings, automatically we assume this is the cause but by the time you see zero numbers, its because the dino has consumed the po4 and no3 and are multiplying and in turn many dose no3 and po4 to bring numbers up not realizing they are feeding these flagellates even more.
Its biological deficiencies that are causing the dino structure and its important though to identify the type of dino for most effective battle.
No light is first key followed by the addition of bacteria to overcome the bad bacteria allowing them to thrive
Prepare by starting by blowing this stuff loose with a turkey baster and siphon up loose particles. Turn lights off (at least white and run blue at 10% IF you have light dependant corals such as SPS) for 5 days and at night dose 1ml of 3% hydrogen peroxide per 10 gallons for all 5 nights which works as an oxidizer. If you dont have light dependent coral- turn all lights off. During the day dose 1ml of liquid bacteria (such as micro bacter 7 or XLM) per 10 gallons. Clean filters daily and DO NOT FEED AMINO OR ADD NOPOX which is food for dinos, however you can feed coral, food which will help no3 and po4 to increase. If increasing nutrients, try to keep no3 to about 5 until you are done battling these cells.
Doing a daily siphoning will help greatly But . . . . . Siphoning will reduce nutrients , so siphon the water into/through a filter sock and save the water and return it back to tank. Obviously clean the filter sock each time.
You can feed fish as normal and if doing blackout, ambient light in room will work for them

 

[CHSUB]

My nutrients are lower than yours, no3 @ .1 and po4 at .008 ICP tested. Last week I purchased a microscope for fun and as expected found dinos in my 1.5 year old tank. They only become a problem if you let them, increasing nutrients are a sure fire way to do this. I just turkey baste and remove, maybe use a toothbrush to really clean the rock. It comes down to vigorous maintenance or mythical solutions…your choice and GL.


October 20, 2025

 

[CatsandClowns]

I wouldnt up front dose nitrates as when we see zero readings, automatically we assume this is the cause but by the time you see zero numbers, its because the dino has consumed the po4 and no3 and are multiplying and in turn many dose no3 and po4 to bring numbers up not realizing they are feeding these flagellates even more.
Its biological deficiencies that are causing the dino structure and tank is already doomed. Its important though to identify the type of dino for most effective battle.
No light is first key followed by the addition of bacteria to overcome the bad bacteria allowing them to thrive
Prepare by starting by blowing this stuff loose with a turkey baster and siphon up loose particles. Turn lights off (at least white and run blue at 10% IF you have light dependant corals such as SPS) for 5 days and at night dose 1ml of 3% hydrogen peroxide per 10 gallons for all 5 nights which works as an oxidizer. If you dont have light dependent coral- turn all lights off. During the day dose 1ml of liquid bacteria (such as micro bacter 7 or XLM) per 10 gallons. Clean filters daily and DO NOT FEED AMINO OR ADD NOPOX which is food for dinos, however you can feed coral, food which will help no3 and po4 to increase. If increasing nutrients, try to keep no3 to about 5 until you are done battling these cells.
Doing a daily siphoning will help greatly But . . . . . Siphoning will reduce nutrients , so siphon the water into/through a filter sock and save the water and return it back to tank. Obviously clean the filter sock each time.
You can feed fish as normal and if doing blackout, ambient light in room will work for them

You are right regarding bacterial and nutrient deficiencies. Though no, its not doomed, dinos can be outcompeted with time. Im not convinced an extended blackout would help though. Also if im trying to promote the growth of beneficial bacteria, id imagine a daily siphoning wont help in that regard in conjunction with a blackout, peroxide dosing, and the introduction of other bacteria rather than the proliferation of the bacteria already present on my live rock. This all seems like far too many things to change all at once, which I imagine will harm my corals more than the dinos currently are or have been previously, especially considering they are almost all highly light dependent. The only thing I will change at the moment is nitrate dosing and avoiding a water change or as you have advised to do so through a filter sock and back into the tank.

 

[vetteguy53081]

You are right regarding bacterial and nutrient deficiencies. Though no, its not doomed, dinos can be outcompeted with time. Im not convinced an extended blackout would help though. Also if im trying to promote the growth of beneficial bacteria, id imagine a daily siphoning wont help in that regard in conjunction with a blackout, peroxide dosing, and the introduction of other bacteria rather than the proliferation of the bacteria already present on my live rock. This all seems like far too many things to change all at once, which I imagine will harm my corals more than the dinos currently are or have been previously, especially considering they are almost all highly light dependent. The only thing I will change at the moment is nitrate dosing and avoiding a water change or as you have advised to do so through a filter sock and back into the tank.

Doomed?? Darn word correct - omit that and i fixed it

 

[CatsandClowns]

Doomed?? Darn word correct - omit that and i fixed it

Okie lil update, I have been manually removing the dinos without dosing bacteria or doing a blackout, I havent noticed any rapid regrowth on the areas of the sandbed ive removed. However, I have avoided touching the glass or algae on the rocks. I'm noticing more growth of film algae between the glass and sand, which I can only hope will smother the dinos. Additionally, I have noticed my first coralline bloom; I'm now seeing specks of coralline all over the rocks, on my wavemakers, and on the weir. I'm going to keep doing as I am for at least the rest of this week. At which point would you recommend doing a water change, once I stop seeing dinos on the sand, a week after, two weeks?

 

[CatsandClowns]

Another update. Over the past week, Ive got an in-tank UV sterilizer ive been running for 9-10 hours(or overnight) in conjunction with wet skimming(turning off for the day and replacing with an airstone) and daily(1-2x) filter media replacement. Ive noticed every night a huge amount of dark, dino colored skim. I haven't noticed any new growth; in fact, the cyphastrea, my only at-risk coral, has stopped being covered by dinos. The sandbed stays slightly clearer each day, though the top layer still has to be manually removed semi-frequently. I will likely need new sand before long.