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· Old man with an aquarium
189 Posts
Discussion Starter · #1 ·
I need some help. For the past few years i have been constantly battling diatom in my tank. I cant figure out where the silicates are coming from or what I am doing so wrong :(

The diatom are easily cleaned off the rock and tank but they show up next day or so.

Tank info:
160g tank been running over 15 years.
Was DSB but have been running BB last few years.
75g sump with live rock and skimmer
No mechanical filtration used
Run BRS GFO (BRS GFO high capacity) and Carbon have change weekly to monthly does not seem to make a difference.
10g fresh water top-off

saltwater: I make my own , was using Red Sea Pro but switched Tropic Marin Pro Reef Salt few years back

for the freshwater past year been using Apex RO unit with a BRS Triple DI saver kit - all TDS are 0. Water stored in 40g Rubbermaid trash cans container

Feeding: once a day to every other day, 1 cube frozen brine shrimp, 1/2 cube of mysis shrimp, soaked in a cup of tank water and then strained in net before adding to tank.

Blueline pump closed loop recirculating with a SCWD 1inch wave maker

2 t5 run at 20% on for 12 hours
3 Kessil 360 at 50% on for 8 hours

Live stock:
1 foxface
2 clowns
1 tang
1 Ras
1 dragonet
2 gammas
3 peppermint shrimp
2 rose anemones

ALK 6.5
CAL 450
MAG 1420
Phosphate .004

dont have silicates test but pretty sure i have high level of silicate based on the blooms.

here are a few photos of a few days after cleaning:



When clean

All suggestions welcome.

· Old man with an aquarium
189 Posts
Discussion Starter · #3 ·
I will look at the photo on my computer later. Are you sure it isn't cyano?
Hi Jerry,

thanks for helping out. looking forward to hearing from you once you see the photos.

Could be but cyano i have had in the past (in my DSB days) and is more like a slime that comes off in layers. This is more of a dust and comes off in clouds if you wave you hand at the rock work. i might have some chemclean i could try.

I have also tried a few things to eliminate it but with no luck. huge (40g) water changes weekly for a few months, not feeding for days, reducing light cycle, reducing light intensity, leaving lights off for 3-5 days, daily syphoning it off rocks and tank. GFO.

Leaving lights off is the best, it completely go way in about 4 days but once i start turning the lights on it starts coming back.

· Old man with an aquarium
189 Posts
Discussion Starter · #5 ·
also, want to add that my pH has been very low for years. 7.6-7.8 Started around the time i removed the sandbed. only time i can raise it using Kalk but it make the boom worse.

· Old man with an aquarium
189 Posts
Discussion Starter · #8 ·
Started a 'few years ago'......what's changed a few years ago? Certainly no diatom guru, but hate seeing a long time reefer getting to his wits end. We do love our 'detective stories' on occasion, so I sure hope we can get to the bottom of this for you.

Yes, the 'powdery' description makes it sound like diatoms as opposed to a 'film algae'. I don't know if the 'web' is getting confused, but it had always been a fresh source of silicates was the cause......and when depleated, the diatoms died rocks, new sand BOOM! BUT they die off. But a quick search on the web tonight is also now throwing 'too much lighting', and NO3 into the mix as well.....NEVER HEARD OF THAT! THAT sounds more like they're getting things mixed up with 'brown algae'.

You seem to be doing everything right....0 TDS, brute trash cans....most often suggested.

Just for giggles, did you get new lighting about the time this started? And just for another giggle.....what is your NO3 readings like recently?

Pulling for Ya,
A lot has changed from when I first noticed it. I would say it started after the cyano battle which lead me to remove the DSB around 4 year ago. lights did change to LEDs but i feel it started before that. Its been a while since i tested NO3, let me pull out the test kit.

· Old man with an aquarium
189 Posts
Discussion Starter · #9 ·
I looked at the first photo as large as I can get it.
Are the bubbles attached to the red substance, it appears so?
the stuff on the top of the rock on the right hand side does look like DINO
kind of stringy with bubbles.
Might try bumping up the phosphates a hair.
I am starting to think it DINOs too. it would seem everything I been doing (trying to be crazy clean) is feeding them. I have been getting so frustrated that right after a water change they would come back hard. I was thinking i had high silicates and or phosphate in my source water. Now I am thinking i have been too clean...

what is the best way to raise No3?
Q:thinking i should remove my GFO?

I am running a Brightwell No3 brick and Xport po4 brick
Q: I am thinking I should remove the bricks?

Q: should i order a UV sterilizer?

Here are some additional photos and a video

Photo and video folder - Public

Link to video -!AnxBIHSbVS3Zou5pczeUCoZKq-e_wA?e=T88l5u




· Old man with an aquarium
189 Posts
Discussion Starter · #12 ·
What I am basing the thoughts of Dino on is the first photo you posted.
In the upper right hand corner of the photo the rock comes from the side of the photo and curves up.
After a bit it makes a sharper climb toward the top of the photo. Just to the right of where the rock sharply curves up there appears to be bubbles attached to stringy appendages of the red stuff. Is this correct?
incorrect, the photo is a little miss leading, the bubbles in that photo are on the glass and not in stringy appendages of red stuff.

However, if i let it build up long enough or when i cleaning it does get stringy and bubbles attached.

· Old man with an aquarium
189 Posts
Discussion Starter · #14 · (Edited)
its acts like Dino.

color is brown to red
all over rock and all sides of tank
gets lighter after lights out
goes crazy after water change
gets stringy and bubbly
lower PO4 has not helped
full blackout for 5 days reduces it but does not eliminate

will try and go slow but here the current plan of attack:
Increase feeding and do not strain frozen food
Remove GFO
Continue to use Carbon
Reduce light cycle from 12h to 6h
Reduce white light and increase blue in LEDs
Increase T5 intensity
Raise temp
Raise pH to 8.4
No water change
continue to manually remove
stop dusting off rockwork and siphon instead
siphon to waste bucket (instead of siphon through filter sock to sump)

looking into UV Sterilizer

any thoughts on uv sterilizer vs algae scrubber for the fight?

· Old man with an aquarium
189 Posts
Discussion Starter · #18 ·
Frist off, big Thanks to Jerryclunsford and Hackshobby for helping me zero in on the problem algae. Knowing what you are dealing with make a huge difference. So thanks again guys!

Quick update: Look like good news, Dino's seem to be on holiday and have not moved back in with a vengeance as of yet.

So far here is what's been done:
Removed GFO
Increased flow through active carbon
Raised temp from 78 to 80
Raised pH (via kalk) from 7.6-7.8 to 7.9 - 8.1 - targeting 8.4 but going slow
lights change from 12 hours to 6 hours
  • LEDs from 50% color to 25% color towards the blue side
  • T5 from 25% to 100% intensity
Syphoned problem algae from rock and tank walls right before lights out
No longer rinsing frozen food

Also, as a bug plus the corals and nems are enjoying the extra blue light..

Battle log photo folder share - Battle

Day 2 photos:




· Old man with an aquarium
189 Posts
Discussion Starter · #21 ·
Stop your water changes as that feds them I would syphon as much out out and then go for a 3-5 day black out once all signs of-it have gone give 1 more day of black out then slowly lift light level up to normal..
Welcome to TRT and thanks for suggestions. I have had a few Reeflos over the years.

Yep, no water changes, seem to be helping a lot. I did a 5 day blackout (lights out) and ramp lights a month ago and everything looks good but it all came back. My Nems took a big hit during the blackout and lost a lot of their color, even with feeding them.. I am planning on doing another full blackout (cover walls of tank with cardboard) but waiting for the Nems to have a little more color first.

· Old man with an aquarium
189 Posts
Discussion Starter · #25 ·
Got the NO3 test and it around 3 ppm.

Overall the tank is looking much better. Dinos on the run and there is less after each syphon. Its also taking longer to reappear on the rocks and tank walls.

Few observations:
Coraline algae growing again
Seeing some green algae
also some minor bacteria blooming (white cloudy water)
Dino still have a strangle hold on most of the corals but the corals are now starting to fight back

Over I feel like there progress in the right direction and I am putting in less work :)

few photos from today



· Old man with an aquarium
189 Posts
Discussion Starter · #28 ·
Its been about a week since I cleaned the tank and there was a small amount of backward progress. I think this we due to me forgetting to change the LEDs from white back to blue after I last took photos :(.

We lost the Sailfin tang and a few of the corals are having a hard time but still way better than before when the dinos were suffocating the entire tank.

I am also noticing a lots more coralline growth (tank walls and floor) and green algae :)

Here are the photos from today and (link to all photos so far Battle Photos):

After clean the glass




After cleaning rock




· Old man with an aquarium
189 Posts
Discussion Starter · #30 ·
I'm sorry to hear you lost your Sailfin! They are a favorite fish of mine.

You will expect Green algae to initially take off. It's able to adapt to the higher levels fastest and there isn't a bunch of stuff that eats it yet. You might stock up on clean up crew if you are getting low, also pods that eat the algae will naturally multiply in time and keep this in check.

The trick is to hit a level you like and be rather steady with it. The animals will adapt and the tank will maintain a natural rhythm. Like with lighting and other parameters it can take corals months to adapt and in the meantime it's all the nasty stuff that takes off when major changes happen.

Thanks Whiskey for the kind words.

· Old man with an aquarium
189 Posts
Discussion Starter · #31 ·
Update.. Tank is really starting to look great.

Since my last post, i've
turned lights all the way to blue and turn the intensity down a bit
Last syphon was 3 or 45 days ago

Live Apex-PODS and Tigger-PODS

Added the follow to my feeding rotation
Roti Feast
Phyto Feat

Here are the photos




· Old man with an aquarium
189 Posts
Discussion Starter · #33 ·
Wanted to check in and finish the story here. I finally beat them :)

Shortly after my last update I turn up my lights and the Dinos came right back. I got super frustrated and almost called it quits.

So i told myself before i shut down the tank i try the last results. Dino-X. Dino-X did help but did not solve it. it came back again after a month or so.

My next thought was ill just scrapping this whole tank and buy a new one, but i like to keep my fish and rock. I know i could not simply put the rock in a new take so i decide to see what would happen if a dried a few pieces out in the sun (about half my rock). I left them out for a week or two until they were completely white (all dead) and then put then back into the tank. low and behold this really seem to help with the Dino problem. They were no longer ruling the tank. they were manageable and my fish were no longer dying. they were still there but i had to look for them.

I lived with them at that level for a few months until i came upon an article Is This the Dinoflagellate Treatment We’ve all been Hoping for? | Reef Builders | The Reef and Saltwater Aquarium Blog where they raised the tank water to 84 and that eliminate them. I figured it could not hurt. set my apex to 84 and watch then disappear in a day or 2. kept the tank at 84 for a week or so and then dropped it back down to my normal 78. they were gone :) i was even able to turn my led and T5s all the way up. and the best part i was able to do a water change after more than a year.

I have since bought a UV sterilizer to make sure i dont see them again.

Its been a few months now and still no trace. Hope this story might help someone else as this 3 or 4 year battle almost took me out. .
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