Tropical Fish Forums

[Oskar11]

Hi!

I must admit I didn't do enough research before using a new product but I'd like to share my experience.
Last night I added my regular dose of KNO3, KH2PO4 and Seachem Potassium to my 20 gallon planted tank. I keep NO3 at 15 ppm, PO4 at 1 ppm and Potassium is probably ca 20-30 ppm. In addition I added 30 ml of Flourish Excel. This is three times the recommended dose at first use. Result - in the morning 11 of my 24 Cardinal Tetras had passed away along with most algae. Also a lot of unwanted snails were at the waters edge. I had read that Flourish Excel OD would help with the algae (which wasn't too bad anyway). But I did not find out if dose was recommended 3 x of first time dose (10ml per 40 l) or 3x regular dose (much less). I suspect the latter.
So please share your experience about Excel and fish safety. And be warned.

Thanks

[DaleJr]

I am wondering WHY you would use the 3x recommended dose. I am a dry ferts person myself and planted person.

Excel, as I am sure you know, is a Carbon source therefore when you dosed 3x recommended dose you ZAPPED all the o2 out of the tank.

I would recommend determine what is causing the algae (lighting, photoperiod) instead of triple dosing.

[Oskar11]

Thanks for the reply Dale. Looking back I am sure myself why. Tha algae in my tank was not too bad at all. I had decided to try Excel (not for algae removal) and since I had read about overdosing to get rid of algae, I decided quite hastely to experiment this too. It was foolish of me not to think things through.
But I am very interested about the chemical side of what actually happened. Why/how does excel "zap" the o2 out?

[carpalstunna]

Here is an article I found on using excel to treat algae. http://www.aquariumslife.com/featured/algae-control-with-flourish-excel/

I have found the spot treatment method to be highly effective and safe as you are not adding an unsafe amount of carbon to your tank. I think that if you were going to do the whole tank method it would be best to do it in when your lights first come on so your plants photosynthesis would be at a rate they could absorb much of the carbon and your fish would be less likely to suffer oxygen deprivation.

Also excel contains glutarldehyde. Glutaraldehyde is a chemical that is very similar to formaldehyde. It is a powerful disinfectant, sporocide and fixant. I believe it is or was actually used to sterilize dental equipment. So I feel like anything with a description like, that you OD, is obviously gonna have a negative effect. I know that not real sciency, maybe someone else can elaborate on the molecular reactions.

What forms of algae were you experiencing that led you to this method?

[DaleJr]

Here is a great link for you to use to identify the type of algae you have. Also it tells you HOW to get rid of it.

Just scroll down to the bottom of the page.

http://aquariumalgae.blogspot.com/


Excel can even KILL some forms of plants. Spot treatment is what I use Excel for anyways not as a carbon source since I am using pressurized co2.

[carpalstunna]

I had a terrible amounts of Cladophora algae in my tank at one point. Nothing would eat it and I found that a thorough cleaning, soaking my wood and affected gravel in hydrogen peroxide as well as spot treating with excel was highly effective. Obviously if most of your algae can be manually removed that is preferred.

[Darkblade48]