Welcome to ScapeCrunch

We are ScapeCrunch, the place where planted aquarium hobbyists come to build relationships and support each other. When you're tired of doom scrolling, you've found your home here.

Anyone else do blackouts as algae treatment?

I've done it multiple times in the past for extreme algae cases. Plants will suffer, but it's not always the end of the tank's lifespan. Nowadays I prefer to try to catch the algae issues in advance so they don't get so bad, and fix it when I can. I consider it one of the final "nuclear" options for algae management.
 
Never had to do the full blackout either though I might not be far from trying with my staghorn war. It’s got to be a constant battle with all that natural light flooding in, do you just run a lower intensity light for your viewing?
I assume you cease dosing for a few days during this?
I have about 37 ft of picture windows around my living room tank, nothing direct only ambient but wonder if this is contributing to my issues. Come winter it’s going to be struggle as the sun hits the largest window.
 
Blackouts work very well for nature style scapes (or shade plant/slow growing plant scapes), and does not work as nicely for stem plants or high energy tanks. Works for some stubborn algae types that regenerate fast even with algicide usage. I think its useful for less skilled aquarists that are not good at remedy work.
 
Id be trying to figure out why I kept having algae so much Im thinking about blackouts and all these "remedy methods" for it, lol

I know most of us here keep clean tanks. That leaves struggling plants as the only other cause of algae (even if the plants struggle isnt visible yet) I also know most here know how to have enough co2. That leaves a very good chance you just need more ferts, likely macros

From over here in the dark Id go out on a limb and say that would fix 8 out of 10 issues for anyone reading this thread ;)
 
Last edited:
It’s got to be a constant battle with all that natural light flooding in, do you just run a lower intensity light for your viewing?
I assume you cease dosing for a few days during this?
This was back in 2020 when I was in another apartment. Yes, the afternoon sun was causing a problem and I did try to balance the light intensity. I had GDA and hair algae that wouldn't go away.

I decided to try the famous and old One Two Punch whole tank algae treatment. @plantbrain has also written about this in the past.

The basic idea is to do more damage to algae than you do to your plants. It's key that your plants are as healthy as possible before trying something like this.

So, thoroughly cleaning the tank and confirming your husbandry practices are correct, as @Burr740 says - CO2 is dialed in, and that you've tried less drastic options, are what you do first. Then, if algae continues to hang on, this can finally push algae over the edge.

It worked for me in this case. YMMV.
 
This was back in 2020 when I was in another apartment. Yes, the afternoon sun was causing a problem and I did try to balance the light intensity. I had GDA and hair algae that wouldn't go away.

I decided to try the famous and old One Two Punch whole tank algae treatment. @plantbrain has also written about this in the past.

The basic idea is to do more damage to algae than you do to your plants. It's key that your plants are as healthy as possible before trying something like this.

So, thoroughly cleaning the tank and confirming your husbandry practices are correct, as @Burr740 says - CO2 is dialed in, and that you've tried less drastic options, are what you do first. Then, if algae continues to hang on, this can finally push algae over the edge.

It worked for me in this case. YMMV.
I did a modified One Two Punch a few years ago in a tank that also had a lot of ambient light. I had been struggling with algae in a nano tank and was doing maintenance every day or two (possible only because it was a tiny tank), but it regenerated so fast. Manual removal, hydrogen peroxide spot dosing, and changing water, but not much improvement. I did a partial rescape, added a filter, and added more fast growing plants and that helped, but a few months after that I did my version of the Punch and then drastically cut back my photoperiod after and that did the trick. I didn't cover the tank though, just turned off the light. And the tank was pretty immaculate after that blackout period - a classic low light/easy plants situation that stayed that way until I took the tank down.

This was my second tank ever, so the algae situation was self-inflicted to begin with. According to my journal, I didn't even realize how much ambient light the tank got until I did the blackout period and I'm not sure why I didn't cut the photoperiod down earlier in my struggle. Some things you have to learn the hard way, I guess.
 
I’ve only done blackouts for severe cases of cyano. I think GDA doesn’t really require a blackout even in the most severe cases, it kinda has its lifecycle where it peaks and then turns fluffy which you can vacuum out. Focusing on cleanliness and nutrient stability has worked better for GDA, string algae, diatoms - less effort overall.
 
Back
Top