Flourish Excel causing algea

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

graucow

Aquarium Advice Activist
Joined
Jan 28, 2014
Messages
176
To anyone with experience using flourish excel, I wanted to use flourish to increase the carbon in my tank and make the plants grow fast/better. I have read online that flourish excel usually helps people get rid of algea since their plants can now use more nutrients. However I noticed when I dosed flourish excel it caused algea blooms, I even tried using a half dosage but it still caused algea blooms and when I stopped using it all together the algea went away. Does anyone know what might have caused this? The tank is a 20 gallon high, root tabs are used to add nutrients to the substrate. Not running Co2 or anything so I would think the plants are Co2 limited.
 
Excel is an algaecide.... I don't think it would cause algae.

What are the specs of the tank?

Lighting brand + model + hours per day
Water changes


What type of algae are you experiencing? any pictures?
 
Same as above - I use it to discourage green algae and it’s highly effective on black-beard algae.

Odd one.

Do you have ammonia reading? It’s also a bactericide in high enough dose so all I can think of but have never really noticed anything there either, even at 4 or 5 times normal dosing.
 
Your not balancing it all out. I'm not an expert, but getting to by experience. I have 2 bigger tanks. I use excel on both. One thrives with it. And the other one don't. The one that thrives has lots of plants, canister filter( lots of water movement), enough waste with the amount of fish I have, heater, good old light, and lots of love with water changes weekly 50-70% (that varys). But, always change out half the water no matter what. And tank is in a corner of my living room. Now my other tank has betta's 55g. Not very many fish ( not much waste) 2 hang on the back filters, air stone, heater, a ok light, some faster growing plants, 1 or 2 slow growers. Same rutin with water changes. This tank gets algae, a lot! I know the cause. This tank is in my dinning room where there are sliding glass doors that let in a lot of sun light. There's not enough water movement, and there's not enough waste from my betta's. I'll be moving my tank to another room(darker) or get some curtains. A canister filter and some different fish with my betta's. So, I hope this helps. I also use root tabs, dose excel, and some iron, and potassium switching the iron and potassium on and off one day dose one, next day dose the other. The main problem for me is all the sun light, but everything plays a part. There's gotta be balance for planted tanks to thrive. Good luck to you. And make sure your dosing right amount too.
 
Excel is an algaecide.... I don't think it would cause algae.

What are the specs of the tank?

Lighting brand + model + hours per day
Water changes


What type of algae are you experiencing? any pictures?
I don't have the specs of the tank and I do not live near it usually so it is difficult to get all the specs. Water changes about once a month, heavily planted maybe 10-20 plants. Tank is 40 gallons with a backpack canister filter. Lights are blue and white LEDS that are on about 9 hrs per day the algea is black beard. I've had similar problems with dosing excel and more algea appearing in my 20 gallon high tank which uses rgb leds and has a hang on back top fin 30 gallon rated filter. I would say both tanks are understocked.
 
Hmmmm, that's a tough one. Excel is a superb product at wiping out BBA.....

BBA thrives in high organic tanks, which sound like the one you describe. 1 x monthly water change means there will be lots of organics in the tank "feeding" BBA growth...
 
Yes, tricky. The excel may be triggering something but it definitely is an algaecide. I think as well the main problem is elsewhere.

Under high light it is possible to grow BBA even with double-dosing excel.

Reducing lights to 7 hours and cutting blue light to 50% I’d try and then work back up.

Water changes as well.
 
Water circulation may or may not play a part, too. I get BBA where I don't have at least some flow. Plants should be -gently- waving in the current. As the others have said, less lighting, making sure you're fertilizing not too much or too little. (I find that reducing my phosphate amounts help decrease BBA and stag horn quite a bit.)
 
Water changes are needed in greater amount then 1 time a month.
Also I think[years of experience] that the blue light in freshwater is a algae advocate.
If you can run the blue less I would..
By reducing the amount of blue light I run on my tanks [60 +] I have reduced BBA dramatically if not almost completely..
It is NOT the excel that is for sure.... Try targeting it to the algae and see what it does..
 
Unfortunately I don't have the ability to do more water changes becuase I'm usually away at school I will try reducing the light tho I have no control over the amount of blue light that is emmited, looking into getting new lights when I get the funds
 
From advice on here, I taped over some blue lights here with masking tape and found that helped. This was for a smaller tank that was continuously getting algae issues and poor plants.
 
From advice on here, I taped over some blue lights here with masking tape and found that helped. This was for a smaller tank that was continuously getting algae issues and poor plants.
Ok, I may try that. Did it help with plant growth as well? Just wondering, my plants grow very well in my 40 gallon but struggle in my 20 gallon which is where I really saw an algae problem after adding excel (lots of green and brown algae). It uses RGB leds.
 
It did, the java fern had nitrate deficiencies - probably others. Too much light and not enough ferts / CO2. It did a lot better after masking LEDs but I had to experiment a bit on how many.

The trouble is blue light penetrates water very well so a little goes a long way.
 
It did, the java fern had nitrate deficiencies - probably others. Too much light and not enough ferts / CO2. It did a lot better after masking LEDs but I had to experiment a bit on how many.

The trouble is blue light penetrates water very well so a little goes a long way.
How were you able to tell it had nitrate deficiency? I notice lots of holes in my older leafs as well and they are not being eaten is this a sign of a certain deficiency?
 
How were you able to tell it had nitrate deficiency? I notice lots of holes in my older leafs as well and they are not being eaten is this a sign of a certain deficiency?



https://www.google.com.au/amp/s/www.pinterest.com/amp/pin/360710251374411164/?source=images


These may help. Generally I find pinprick holes on lower leaves to be potassium deficiency.

I get floating plants under high light go very pale (sometimes quite quickly) which I tend to think of as the plant trying to adapt to high light and low ferts (from test work) / low CO2.
 
Back
Top Bottom