Green cyano?

[dmolavi]

Take a look at this...Is this green cyano? I sucked a bunch off my rock tonight, and tried to get as much out of the sand bed as possible w/o disturbing it too much (about 99% of it was on the rock, just a few isolated spots in the sand). It's a little tough to see, but it's holding down those bubbles on the rockwork. Total area of all the patches was probably around that of a playing card.

Here are the tank readings tonight:
pH: 8.2
Ammonia: 0
Nitrite: 0
Nitrate: 0
Phosphate: 0
Calcium: 440
SG: 1.025

It started popping up once I added my new LED lights, which were on for approx 10hrs a day. Today, I cut them to 8hrs, and did an approx 40% water change (even though the parameters were good). The above readings were taken prior to the water change.

FWIW, one of my snails must've gone to the big fish tank in the sky somewhere in the rockwork. I haven't seen it in about 3 weeks, but last week, did 5 20% water changes over the course of 5 days because of that, so that I could get any baddies from his decomposing self out of the water column.

I have a HOB skimmer running, producing moderate skimmate. Tank is stocked w/ 2 clowns, a high-fin goby, pistol shrimp, cleaner shrimp, 2 featherdusters, 1 snail. This is a 20g nano tank.

Any idea what else I could be doing wrong, or what I need to do to get rid of them that I haven't already?

Thanks in advance. I hope I provided all the info needed.

Edit to add: I knew I forgot something. I feed on Monday, Wednesday, and Friday nights, alternating between pellets and PE Mysis.

 

[Frankie_Garcia]

Cyano from what I have learned comes from phosphates. You're phosphate level can read 0 because the cyano is a bacteria and it feeds off of the phosphates. If it indeed is cyano. I put a bag of phosguard into my system and cleaned it off and that did the trick. Also, is there good flow to that portion of rock? If not that could be another issue of cyano.

Never seen green cyano. Before, could it also hair algae?

 

[dmolavi]

I can grab phosguard, just in case, but I had 0 phosphates before they appeared, too. The tank is not in direct sunlight, either.

That area of rock does have good flow, yes. Here is an FTS:

The mystery stuff is appearing on the top of the "bridge" rock. I did move the powerheads the same day as I installed the new lights, so the flow pattern was modified.

 

[Frankie_Garcia]

Also, are you using RO/DI water for top offs? Or tap water?

 

[dmolavi]

RO/DI. Zero TDS on the product water.

 

[Frankie_Garcia]

Well with it being a bacteria it will trick you into seeing your phosphates as 0. But I would clean that stuff off the rock, do a 5 gal water change and throw a bag of phosguard in there

 

[dmolavi]

I did a 5 gallon change tonight, and siphoned it off. We'll see what the change in the lighting schedule does, as well.

I can get some phosguard in a day or so.

 

[Frankie_Garcia]

I have had battles with cyano for a long time but mine was a flow issue. I tried the chemicals and nothing really worked till I got phosguard

 

[dmolavi]

I'll tweak the flow, and see if that helps. If not, I'll do phosguard, although since I've always had 0 phosphates, I'm skeptical that's the issue.

 

[Frankie_Garcia]

You don't have a over feed so don't think that's the issue

 

[Sniperhank]

I would do larger than average water changes to address the nutrients in your water column. The readings might be 0, but it is being consumed by the cyano at this point. Increasing the flow will help, but the nutrients will still be there and appear in an algae outbreak. A product like phosguard can also help with maintaining the levels, but a large water change will get you ahead of the game first.

 

[dmolavi]

Grr...even though I already did a 100% change over the course of 5 days just last week? Tonight I did 40%.

 

[Sniperhank]

Hm, well siphon out the cyano and see if it returns. It has to be feeding off of something.

 

[dmolavi]

I couldn't get it all, but I got most of it.
I re-positioned my powerheads to their previous positions (well, as close as I could get them), and cut the lights back to 8hrs a day.

 

[dmolavi]

Could this be blue-green algae, instead of cyano? If so, does it really matter?

And here an interesting article on the topic...using diatomes to prevent other algae:
Hot Tips: Algae Control — Advanced Aquarist | Aquarist Magazine and Blog

 

[dmolavi]

I'm going to do another 30% PWC in about an hour, and will try to get the gunk I missed last night. We'll see what happens.

 

[Sniperhank]

You are on the right track, that's for sure.

 

[dmolavi]

PWC done. Fingers crossed.

Sent from my SPH-L710 using Aquarium Advice mobile app

 

[dmolavi]

Bah, it's growing back on the rock again. It's not red, though, like most cyano that i'm reading about. It's dark green.

I started a phosguard run yesterday, so hopefully that'll kick it in the pants. I need to get a salifert PO4 test, too, since my API test kit doesn't have the resolution required (goes from 0 to 0.25 ppm), so I could have had high PO4 and it just didn't register w/ the kit.

I'm pondering the thought of turning off the lights for a few days, too. I have duncans, torch, frogspawn and zoas...they should be OK for 72 hours of no light, right? The room has ambient light in it during the day, so it won't be complete darkness.

 

[dmolavi]

Continuing the PO4 discussion, should I siphon below the surface of my sandbed when I do my PWCs? Right now, I just try to get any loose junk off the surface, but don't push the siphon into the sand at all.