Hi @kellyboy47 got your PM. Apologies, tried condensing the two posts whilst on the move this morning and ended up erasing both. Repost below:
Do you have a full tank shot
@kellyboy47 as it didn’t appear in the attachments.
10. Inhabitants. 3 x Blue Acara (Large) 2 x Bolivian Ram, 1 x Rainbowfish, 5 x Corydoras
Any shrimps? Any snails? If not you can treat for cyano effectively, but the stronger treatment most use will be lethal to invertebrates. You can use phytoncide (invertebrate friendly) after manually removing every speck of cyano you can. Harder work, but also effective.
And this is my current lighting period
Dawn 9-10 White 0% Blue 40%
Sunrise 11-1 White 85% Blue 85%
Sunset 5-8 White 5% Blue 40%
Dusk 9-10.30 White 0% Blue 0%
13.5 hours of light requires a healthy setup under those lights. Right now it will be exacerbating the cyano problem, as it is obviously photosynthetic. Longer blackouts are usually ineffective as you weaken plants in that time. If that system is already in detriment, the additional decay from failing plant matter will add to the problem. You switch lights back on, Cyanobacteria divide faster than plants recover. Plus they have everything they need.
As
@tam has posted:
There is no point swapping out substrate, it only needs invisible traces to come back. If you search the forum for cyano there are loads of posts on getting rid. It's good to work out why - sometimes it's low flow areas and excess mulm so a good clean and redirecting flow an help. Once it's there though, fixing the initial problem doesn't necessary get rid of it, it tends to hang on.
You want it on the back foot. That is achieved through a well oxygenated system. It exists as there’s an oxygen deficit in your tank. It’s why planting heavy at startup negates a lot of problems, more plants, more photosynthesis, more oxygen. Even your move was a significant event for your tank biome.
Cyano can fix nitrogen and does, to give it credit, produce the oxygen your system needs in absence of photosynthesis from plants. But only to its own benefit. It smothers everything else, coating surfaces so nothing else gets access. It’s a survivor, the survivor in fact, adapting the environment to its needs.
To fight this, within the filter that means maximum flow to your media as
@dw1305 has pointed out. This is to provide oxygenated water to your filter media. Anything that impedes that delivery of oxygenated water is again, exacerbating the problem. Less oxygenated water to your nitrifying bacteria, higher ammonia as it isn’t being processed into nitrate. More ammonia and unhealthy plants unable to uptake that ammonia, more issues.
You’re getting it anywhere there’s a meagre amount of light available. It needs removing until the only place it can exist is in the darkest recesses of the substrate, in small colonies where it can be directly dealt with.
There’s already a lot to digest there so will break it down into three simple categories:
- Maximum manual removal of cyanobacteria
- Restoring desired healthy plant matter
- Restoring the system to a well oxygenated state
Practical advice on how to achieve the above in order:
- Maximum manual removal of cyanobacteria
Manual removal by siphon. If using tap water and a mixer tap, you can fill and drain the tank simultaneously by adding periodic doses of dechlorinator. Match the drain rate to the fill rate. This means you can evict the stuff wholesale as you can vacuum up all traces.
- Restoring desired healthy plant matter
Plant up the tank with as much plant mass as you can. Ensure good surface agitation and stick to a fixed lighting schedule and lighting intensity. You want your plants adapted to the rhythm of the day. No curve balls. The consistency sets the plants up.
- Restoring the system to a well oxygenated state
Can’t stress this one enough… If you’re running a low tech tank, surface agitation is your friend. It ensures a reliable, continual and consistent supply of dissolved gases. More rot - provides the required oxygen. Fish dies - provides the required oxygen to break it down. Co2 - keeps it available for plant tissues to uptake. If it’s not needed - maintains equilibrium anyway.
Your substrate age is partly a red herring. You can just dose comprehensively through the water column. The main thing you want is healthy plant root respiration taking place in the substrate, it will make it uncomfortable for the cyano to dominate in the substrate.
If you end up with cyano patches surviving against the glass where there’s light, you can inject treatments into the substrate along the glass to give it a final shove.