# Will Flourish Excel kill fish?



## inwu

I have terrible hair algae boom so I decide to over dosing Flourish Excel to kill them. Actually, this is my first time using the Flourish Excel. I got it last night and put 25mlx3 in my 55gal tank. This morning, the hair algae does look thinner and this is a good thing. But I notice the platy and cat fish looks weird after I add the Flourish Excel. They just don't move that much. I even suspect they are dead. Should I do water change ASAP or just let them sit in until the hair algae get controlled?


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## freshyleif

YES flourish excel will kill fish when over dosed to much. I have done it. I would strongly recommend doing a water change now if it is not to late for your fish already. The best way of using the over dose method that I have heard of on here was to:
1) turn off you filtration and use a small squirting tool like a syringe or small baster to just target the worst areas.
2) Take all the fish out and cut the light time down to around 4 hours then treat with excel and after 12 to 24 hours do a large water change 50% to 80%.
I hope this was helpful maybe someone with more knowledge on this can give you more ways to deal with the algae and not endanger the fish in the process.


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## inwu

Hi freshyleif,

If I just follow the dosing instruction, will it still hurt the fish? I am thinking of following the instruction and kill the algae gradually! (If it work)


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## demen45

Excel will not kill your fish unless you dump the whole bottle in. I use 3x the recommended dosage to treat BBA and my fish are still fine. BBA gone in a few days. Good luck


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## inwu

Not sure if it will kill the fish but I did notice a certain degree of the stress they show! Anyway, I did a water change and they become a little bit normal now! From what I have observed, I believe there's a chance the fish will die or at least become weak! I will post again if my fish die!


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## Tex Gal

I have dosed excel for years. I've never lost a fish. I dose at the initial amount recommended. I squirt it on the algae going around my tank every day until I have hit all the places I see the algae. I leave my filter running unless the algae is right where the filter blows. If that's the case I turn it off for only about 10 min and then turn it back on. Excel has a tank life of 24hrs so you should be able to do this every day.

Excel doesn't kill some of the hair algae. It does great on BBA. Could that be what you have?


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## Hassles

The recommended Dose rates for Excel appear to be fine but caution is required if you intend over-dosing. I have known people who have killed their Discus through an Excel over-dose (3 x recommended dosage for algae cure) and another friend almost lost her Clown Loaches to an relatively mild dose of Excel. They were undertaking a water change, removed the water, dosed the Excel and topped-up the tank. Had they topped-up the tank first berfore dosing the Excel the loaches 'may have' suffered less. Obviously many people are experiencing wonderful algae cures using Excel but.... exercise caution.

take care


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## fibertech

Let me get this straight. You dosed 3 times 25ml for a 55 gal? For a total of 75ml? Holy Motherload Batman.
I dose 7ml daily in my 55 and when I was ODing I would not go over 15ml.


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## intothenew

I have, in the heat of battle, dosed as much as 1ml per gallon. In a 55g with substrate and hard scape that's about 45-50 ml max. I ramp up the dose over a weeks time, that gives the enemy time to realize that I'm serious, and hopefully avoids any friendly fire incidents.

I have yet to experience an enemy that could withstand a week of that full artillery barrage. As has been said, aim your weapon directly at the enemy.

At that rate, I do notice a dip in moral of my troops.


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## inwu

I probably lost one zebra loach. Can't find it anywhere! I have done a couple of water changes during the week the rest of them seem to be fine. Anyway, I will say the Flourish Excel is really effective to deal with the hair algae! I think my tank is under control now!


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## Justice Bucket

It probably also depends on your present tank parameters also. I have dosed a little more heavily at times and I notice signs of stress on my fish. The corys remain static on the substrate. The lamp eyes freak out and the weaker ones die. My betta seems disoriented. My ph is generally low though and the extra Excel might have lowered it to unbearable levels (?)


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## neilshieh

an SAE would be more useful, eats BBA like salad. or you could try squirting hydrogen peroxide at the algae.


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## Euphoricdazed

This product, made my beta fish disoriented and he turned black quick, thank goodness I always check him mutiple times after a water change because he would have been dead if I didn’t have a back up tank.


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## Michael

Welcome to APC!

This discussion is over 10 years old, so you aren't likely to hear from any of the original posters. I'm glad your betta survived.


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