Reef Central Online Community

Go Back   Reef Central Online Community > General Interest Forums > New to the Hobby
Blogs FAQ Calendar Mark Forums Read


User Tag List

Thread Tools
Unread 02/07/2020, 07:13 PM   #1
RC Mod
Sk8r's Avatar
Join Date: Feb 2006
Location: Spokane WA
Posts: 34,628
Blog Entries: 55
ALGAE& CYANO (red slime): how to and how not to have it

First, there are things that look like algae and aren't: cyanobacteria is, well, bacteria, properly a bacterial sheet, and it IS generally reddish, like a film, with bubbles in it. It's very old: during the Permian Extinction (qv), back before the dinosaurs, it oxygenated our planet, keeping us alive, but despite our debt of gratitude, we don't want it in our tanks.

To kill it, turn out your lights for 3 days, that's all. Don't wrap your tank, just keep the curtains drawn and the lights off. And if you have corals, bring your lights up gently on the 4th day, then full on the 5th. Won't hurt your coral. If you have a good skimmer, it'll work hard and fill fast. If you have less than a good skimmer do a 30% water change, wait a day, do a 20%. Do this whole operation once a month. It may recur, particularly if a ray of sunlight can reach your tank, but keep after it.

The other thing mistaken for algae---and mistaken for cyano--- is, well, animal: dinoflagellates. It's dirt brown. It's nasty. Part of the cure is to improve your tank's parameters to really-good. There is a stuff called Dino X, which is supposed to kill it, but there're many, many varieties. Suggest IF you try a treatment like that you either have a killer skimmer or stand ready for a 30-20-20 water change, ie, add another day of rest then 20% water change to the prescription for cyano cleanup.

Now to the real thing: algae. Plants. There are good plants, like cheato moss, which you can grow in a lighted sump, which helps uptake phosphate, which is algae fuel. [Do NOT let cheato loose where it can reach your pump! it's like green wire, and makes a mess.] There are bad plants, like common hair algae. First of all, realize that ROCK and sand often contain phosphate, which soaks OUT into your tank and flows in the water. Algae love excess phosphate. Without it, they die. Various products like Phosban (a ferric oxide) in a reactor (they optimistically provide a sock, but it's not the way to go---you need a reactor for a tank above tiny-tiny) The trick to using Phosban is to change it out about weekly, because once it's sopped up all it can hold, it sits there looking righteous, but in reality it's useless now. Needs to be tossed and new ferric oxide installed. You may keep this up for more than a month. Or two. THIS is why we say don' t use raw dry rock: get conditioned rock or condition it yourself.

Then there is the rock that keeps on giving. You think it's conditioned. But it has so much phosphate deep inside it, it goes on triggering green growth for over a year. Up to two years. Nasty situation. I am not a big fan of treating a tank with chemicals, because they can turn on you if you don't have a really good skimmer, and many beginners don't. But if you have the Never-Ending Supply of phosphate, this is the time to head for Fluconazole, aka Reef Flux, and just follow instructions immaculately, and stand by to do that 30-20-20 series of water changes.

There is also bryopsis, which I recommend you Google for a pic---because telling it from hair is not always easy. Fluconasole is a treatment. Again---skim! and do water changes.

Green, red, or brown in your tank is a pest and a problem, but it can be cured. If the 'little' solution will work, don't go for the big guns of a chemical treatment. If you HAVE to go to the chemical or drug, look at your skimmer, and be prepared to do water changes.

Age of a tank improves all this. When you have a raw new tank trying to accommodate whatever rolls in, your balances are likely off, or prone to go off, and you get one nutrient or the other feeding a 'bloom' of plants or bacteria or animals. Mature tanks have their own ills. But if you want to minimize your problems, work on your parameters and your flow, and do your water changes. Putting in a tiny frag of something hardy is a way of giving yourself a 'mine canary' for bad water (if coral is the route you want to go) ---because coral closes up if the water isn't good. Fish just swim merrily along looking normal no matter what, until they stop swimming. Corals are good alarm systems. So, of course, are your test kits. And a log book, giving your test results. You may not need a log book forever, but while you're learning how your tank reacts to changes and dosing (if any) it is a real eye-opener.


Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low.

Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

Last edited by Sk8r; 07/16/2020 at 10:29 AM.
Sk8r is offline   Reply With Quote
Unread 02/08/2020, 03:42 PM   #2
Registered Member
djryan2000's Avatar
Join Date: Aug 2019
Posts: 441
Awesome read, thank you!

Sent from my iPhone using Tapatalk

djryan2000 is offline   Reply With Quote
Unread 02/19/2020, 08:56 PM   #3
Registered Member
Join Date: Feb 2007
Location: Santa Monica, California, USA
Posts: 2,511
Little known info: Bubble algae concentrate nutrients into the bubble, and thus can survive for a while with no nutrients in the water at all. And bryopsis uses actual roots that extract nutrients out of the rock, also, when there are no nutrients in the water.

Inventor of the easy-to-DIY upflow scrubber, and also the waterfall scrubber that everyone loves to build:
SantaMonica is offline   Reply With Quote
Unread 09/04/2020, 01:16 PM   #4
Registered Member
Join Date: May 2012
Location: Englewood NJ
Posts: 28
Super informative! I had bad Cyano recently and this is the first time I’m reading about the lights. I was told to turn mine down a bit. Thanks!

Omri is offline   Reply With Quote

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

All times are GMT -6. The time now is 03:25 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2022 Axivo Inc.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef CentralTM Reef Central, LLC. Copyright 1999-2022
User Alert System provided by Advanced User Tagging v3.3.0 (Pro) - vBulletin Mods & Addons Copyright © 2022 DragonByte Technologies Ltd.