BBA Algae in the aquarium

Combating BBA with Seachem Excel

Pre Purchase

Having just ordered a 500ml bottle of Seachum Excel I look over at my aquarium, exhausted by the sight of persistent BBA.

Seriously though, BBA can be very annoying and it’s very difficult to get rid of. This post will detail my experience using Seachem Excel against BBA.

I do not dose any fertilisers or use co2 in the tank.


With my tank containing roughly 140L of water I will triple dose daily at 15ml (5ml per 30gal/40 Litres).

I will do this until I see that the BBA has been effected. Once I see it has, I will dose an extra few days. 10 days minimum, then longer if needed.

Seachum Excel could lower the oxygen levels in the tank so I’ll be adding a temporary air stone for the duration.

As always the fish are my main priority so any sign of distress with the fish and I’ll cut back the dosage. I will still do a 30% water change after 7 days, and dose straight after as normal.


I’m hoping that in well under 10 days I’ll start to see the BBA die off. Hopefully within 3-4 days I’ll see signs of the BBA being damaged, pink or white colouration. This will mean that it’s dying off. Once it’s dead there’s a possibility the Otos will then start to eat it.

Hopefully my plants will benefit from the added carbon too.

If it works

If the BBA dies off I will stop dosing completely after the 10 days. However if it comes back afterwards I will start dosing again at the normal recommended dose providing plants benefit and fish are unharmed.

Black Beard Brush Algae in the aqurium


So iv got the Excel and I’m ready to start dosing.

Day 1: 30% water change then added the first dose of 15ml (triple dose). Will update once I see any changes in the tank.

Day 2: No change with the algae. Only did a double dose as I had to go out an hour later so couldn’t monitor the fish encase any problems occurred.

Day 3: Roughly 22 hours after Day 2 dose one of my Diamond Tetras started acting funny swimming upside down and floating off a bit. Put him in a quarantine breeder box so he doesn’t Injur himself. Thought maybe he’s swam into the glass and it’s knocked him funny, as this happened to a Panda Cory and it quickly recovered. Triple dosed again. The Diamond Tetra unfortunately died overnight.

Day 4: Won’t be dosing tonight.

Day 5: triple dosed. Some of the BBA looks a bit white but most of it has not changed.

Day 6: Did not dose. Did a normal dose the next morning.

The triple dosing I’m doing is dangerous I can tell, the fish are hiding and not eating like they normally do.

So now I’m just going to dose at the recommended dose every morning before the lights come on, and I’m going to see if the BBA continues to spread. If it stops then I’ll know the tank is balanced and I can start cutting it out.

No point of me keep cutting it down if it’s going to continue to grow and spread. The BBA is not harmful to any fish so there’s no point in putting the fishes lives in danger for aesthetics.

Day 7: With my regular standard doses I’m going to try and spot dose it over an area and see if it dose any damage to the BBA.

Did a spot regular spot dose over a rock that has BBA on it. Will monitor the effects.

Day 9: The BBA I squirted with Excel has turned pink/red so it seems that it has killed it. Going to try it again on a large piece of BBA on a leaf and see how long it takes to kill that too.

Day 11: So anywhere I spot dose with BBA turns pink/red after a few days which essentially means it’s dead.


Every tank is different and will have varied results. These results are only what is happening in my tank.

The triple over dosing of Excel seems to take too much of a toll on my fish. All my fish seemed fine until one just suddenly flipped out 22 hours after a triple overdose and eventually died. That’s when you know to immediatly stop.

There’s no doubt if I carried on triple dosing more would have died, and I was afraid I’d come home to an entire tank wipe out.

The triple dosing did eventually work though as about half of the BBA in my tank had turned white. White is another indication that it has died. Maybe the red/pink colour means it’s dead or dying and then it turns white, I’m not sure.

The plants themselves

My tank is primarily giant Vallis, and it seems Vallis isnt too keen on a lot of Co2. So i’m thinking of dosing regular liquid ferts instead of Co2, and see how that goes.

Spot dosing works

However, spot dosing the Excel seems to work and is a more safe option. This will however take a lot longer. Use a pipette or syringe and apply the dose (I’m now dosing recommended) directly to the effected leaves. After a day or two the BBA will turn red/pink and this means it has died, and it can’t spread. Fish such as Otocinclus will eventually start to eat the BBA once it’s dead.

Update: I removed all my plants, scrubbed the rocks and tank, and started again, with new plants. Eventually the BBA came back. To really combat BBA you have to ‘balance your tank’, so the lighting and nutrients are balanced. This will stop BBA from reoccurring. In the end I bought 3 SAE (Siamese Algae Eaters), the eat the lot in a day, and they are really active, great fish to keep.