Does this look like a diatom issue?

AndyR83 · Sep 5, 2019

Hi,

I’ve begun to notice some brown discoloration on my rocks and substrate recently. This is my first saltwater tank, and I initially didn’t think much of it. Tonight I really looked closely and then checked online to see if I could find anything like this. From what I’ve read, the story is consistent with diatoms but I’m uncertain whether this is what they actually look like. I wasn’t able to find any pictures that were sufficiently detailed and/or looked exactly like what I’m seeing.

Is this a diatom bloom, or something else? Or multiple things? Or nothing?

Tank Info:
*55 gallons
*40lbs of live rock (came from LFS)
*Started tank w/ bagged live sand substrate
*Tank is about 5 months old

*Running on a Fluval 306 canister filter since starting the tank

(I know this is far from ideal, but I wanted to ensure I was going to be onboard with saltwater for the long haul before investing too heavily, which I’m now ready and willing to do.)

*Lighting is a FluvalSmart AquaSky 2.0 that I have set up as shown here:

(Full disclosure: I have no idea if these settings are any good)

Livestock Info:
*No corals
*4 damsels
*1 clark anemonefish
*1 bubble tip anemone
*7 turbo snails
*2 peppermint shrimp
*1 hermit crab

Water Parameter Info:
*Temp 77F
*SG 1.023
*pH 8.2
*Ammonia 0
*Nitrate 0

Unfortunately that’s all I can test with the standard API master kit.

I’m planning to visit the LFS tomorrow to get a better water testing kit. Is there anything else I should get while I’m there?

Thanks!

Hemmdog · Sep 5, 2019

Are you using RODI water ?

flchamp89 · Sep 5, 2019

Looks like diatoms. I can't decifer your lighting schedule but it looks like a lot of white. You can run at 77 degrees and 1.023 but I'd raise each by a point just to buffer and swings. Canisters can work but need lots of maintenance. Keep it clean.

AndyR83 · Sep 5, 2019

Thanks for the replies! My initial water was store bought RODI. Subsequent top-offs have been with well water. Admittedly, I have no way of identifying silica levels currently.

I'll happily adjust parameters to SG 1.024 and Temp 78F if that'll help. I'll go clean out the canister filter now as well, just in case.

The lighting slowly fades in from black to full spectrum over the 0630-0730 hour, then remains on with that setting for 12 hours. From 7:30pm-8:30pm the full spectrum light fades into 100% blue for an hour, then it goes dark for the night.

I've been researching sumps and skimmers and am just about ready to take this leap. I'm just waiting to find guidance regarding how to best convert from canister to sump without subjecting my livestock to a nasty ammonia spike.

Hemmdog · Sep 5, 2019

AndyR83 said:
Thanks for the replies! My initial water was store bought RODI. Subsequent top-offs have been with well water. Admittedly, I have no way of identifying silica levels currently.

I'll happily adjust parameters to SG 1.024 and Temp 78F if that'll help. I'll go clean out the canister filter now as well, just in case.

The lighting slowly fades in from black to full spectrum over the 0630-0730 hour, then remains on with that setting for 12 hours. From 7:30pm-8:30pm the full spectrum light fades into 100% blue for an hour, then it goes dark for the night.

I've been researching sumps and skimmers and am just about ready to take this leap. I'm just waiting to find guidance regarding how to best convert from canister to sump without subjecting my livestock to a nasty ammonia spike.

I see. All signs point to your water source as the cause of the diatoms. That’s more than usual I’d say for a new tank, especially since you got the rock as live rock not dry. I haul 35gals a week of RODI from the LFS. It’s not fun but it’s part of the hobby, at least until I have a house with good water pressure and a permanent place to setup a RODI filter.

AndyR83 · Sep 5, 2019

Thanks for that insight! I just ordered a 4 stage RODI filter upon reviewing your suggestion and doing a bit of research

jordan10 · Sep 5, 2019

Hemmdog said:
I see. All signs point to your water source as the cause of the diatoms. That’s more than usual I’d say for a new tank, especially since you got the rock as live rock not dry. I haul 35gals a week of RODI from the LFS. It’s not fun but it’s part of the hobby, at least until I have a house with good water pressure and a permanent place to setup a RODI filter.

Do u check you LFS RODI water? Just asking because I was doing same thing and I tested there water out the blue one day and the TDS was at 27 told them about it and they said that it be ok.

Bret Brinkmann · Sep 7, 2019

Looks like diatoms, brown, and green algae. Not a bad thing. Your snails will love it. All new tanks go through an "ugly phase". This is what herbivores are for. Algae growth like this is a sign of a healthy reef.

Bulk Reef Supply has great videos on test kits so you can make an informed decision on what you want. I personally don't use API any more due to accuracy issues I've experienced in the past.

Just remember that algae like this is okay. If you don't want to manually clean it, then get more snails. Nerites, ceriths, gold ring cowries, chestnut, astrea, and trochus snails can help with this. It's fun to have a variety. They all have different foraging location preferences and some have algae type preferences too. But all of those will do well on brown and green film algae. The ceriths eat diatoms too.

WallyB · Sep 7, 2019

I agree with @Bret Brinkmann, your tank rocks are showing early signs of health and are coming to life.

Your tank isn't 5 months old.

Your tank is 5 months young.

Your ROCKS are aging, naturally. Don't overreact. Certainly not any time for treatments of any sort. If ever.

Doesn't matter if your rock was Live and came from a Store. Or dead rock....they all age, just differently.
The Rocks are now in your tank so they will go thru adjustment as folks say (Ugly Stage).
Completely normal as rocks are now exposed to DIFFERENT light, flow, and nutrition.

The only cure.....is Patience (ie Time).

Slowly the brown ugly coating will change, to more and more coralline coverage....since some rocks in your photos have Purple Coraline Algae already. So the Good Algae will spread.
All your rock will eventually look much better.

Here is what I mean...from one of my Young Aging tanks a while ago. (Timelapse: Just over a year)
TOP LEFT is beginning with Young LIVE ROCK.

No harm that you get some critters to graze on the rocks. To keep things from getting out of control.

Snails....and Not too many crabs (if any), since they kill snails, and sometime not nice to other things in your tank (like Fish/Corals)
More small crabs like Blue legged Hermits are better then fewer big crabs.

No harm that you got a RO system. Pure water for your salt water is less worry about contaminants in general.
Your personal RO system will save you money compare to buying water. You'll get return on that investment.

And no harm to continue to watch, should things get drastically Worse. Right now everything looks perfectly good.

Harm come from listening to folks who tell you change this, fix this, add this, I did this, buy this, and you listen and do it all.

The best thing..... if nothing is terrible......is keep your hands out of your Tank and Stop changing things, unless it's to make things more stable, or small/slow corrections as needed. (That took me 20 years to learn, and it's still tough)

and this is same tank....During two Terrible stages (Cyano Outbreak, and GHA Outbreak)
THIS IS Beyond UGLY.

....and why/how did I lead my tank to above? Lack of Patience!!

After just over a year (last photo in the Quad Photo).... when things started to NATURALLY get better with age and stability....I started adding additives/corals-foods to make them color up and grow more, which they did..so I added more and they got better....and so why not MORE!!! Then Kaboom!

That disaster needed action, and it did get cleaned up (Timeline: 3 years ago)

Here are the exact same rocks, with a couple extra Pieces (the Arches)
.....in a Fresh Restart in a Bigger tank (10 inches wider)...4 years later.

I did skip the sand in the new tank, since I couldn't keep that stuff healthy.

To show aging rocks, and getting better over time.
Here is a photo of the New Left Arch in tank above, when I added it to the old aged rocks.
Position is flipped since I swapped the two arches.

It stood out like a Sore thumb for a Long while before it caught up to looking like the rest.

All the best on your journey....wish you great Success.