Seachem Flourish Excel Bioavailable Carbon - Organic Carbon Source for Aquatic Plants 250 ml

I was struggling to eliminate black algae in my 10 gallon tank. I stumbled across this online gave it a try and it worked wonders within a week. I did a touch up dose roughly a week later and the tank looks amazing. I’m so happy I could finally get rid of the black algae that was overtaking the tank. I tired multiple products, plants, and other creatures the past year and a half, and this is the only thing that worked for my tank. If you’re struggling with black algae, I highly recommend trying this product!

In combination with either Flourite or Eco-complete substrates, I've used Excel for years for my planted tanks. With zero buffering capacity (kh) in the pH 8 well water I had, using a CO2 system guaranteed gorgeous plants but dead fish because of the resulting the wide swings of pH. Excel allows me to have a low tech tank and works wonders for the low to medium light plants that I prefer (crypts, anubias, java ferns, along with higher light wisteria and egeria densa used to combat algae from getting established before the plants do). I now have pH7 water with 2 degrees of hardness and will continue with Excel. For my latest tank (20 long), I've been adding 2ml every day -- it took a month for the plants to establish and start growing. I'll taper off to every other day soon. I expected the crypts to completely melt when first planted because, well, they are crypts and that's what they do. But they didn't melt and are already putting out new leaves and coloring up nicely. This tank also has 2 small Amazon swords planted in the higher light areas of the tank -- they lost their original leaves (they were grown emerged) and now have beautiful truly submerged foliage. I don't have any luck using liquid fertilizers or laterite - I'm amazed at all the different kinds of algae I managed to grow when I used them. By using Excel and adding Osmocote pelleted fertilizer deep under the substrate just where heavy feeding plants' roots are, that seems to limit excess nutrients. I've heard that egeria densa doesn't do well with Excel but mine is doing great and growing like a weed while floating over the top of the water. It's never affected my fish, snails or shrimp either.

I haven't used this long, but I have enjoyed the results so far. I have several plants in a 2-gallon Betta tank. I dose the tank with Flourish, Flourish Iron, and this. And I have seen growth within the first week. I have to dose in very small amounts (1 drop is less than half the recommended dose for that size, two drops is too much) but I do see a difference.I have avoided Excel for the longest time because I heard the stories of people overdosing (accidentally or not) and killing everything in their tank. I can dose correctly, but I didn't want to take the risk with something so dangerous to tank life even if slightly overdosed. I am currently cycling the tank that the plants are in, so no fish yet, but I am sure it will be safe even at the recommended dose, let alone half it.I see lots of people saying they "prefer Excel to Flourish." They are completely different products. Flourish is a micro trace element fertilizer. Excel is a carbon-providing fertilizer. They can be used in conjunction, or separately, but they are separate products. They should not be compared "one or the other."The active ingredient is actually a sterilizer, and is used in some algaecide products. So this means yes, it can be used to kill algae. However Seachem does not market it as such, so you will find no official approval of the product as such from them.The bottle, unlike other Seachem product bottles, contains a ratcheting child safety cap. I see some people say it breaks easily on them, but I haven't had mine break yet. This has a cap like that for a very good reason. This stuff could be dangerous. Not only can some people react to it if it touches their skin or they breath it, but it should be kept well away from anyone who might think it would be a good idea to pour it in a tank, because "it's a fertilizer, so it'll be good for the plants." All fertilizer products should be kept up, but if you overdose with Flourish, you are likely only to have an algae problem if you don't do a water change soon enough. If you overdose with Excel, it will kill everything in the tank.

I bought this to help raise the carbon in my freshwater planted aquarium and hopefully kill off some of the beard algae that had taken over. It works well. It definitely does the job of raising the CO2 but I have not had any luck in it killing the beard algae. The plants seem to be happier and growing great since adding. Product came as pictured and undamaged. Would highly recommend.

This stuff is awesome. My tank had the hard to remove "black beards algae." Scraping, cleaning, sponges, razor blades.... nothing would remove it. Got a recommendation to try this. 2 capfuls and 4 days later and the algae is almost gone, a week later and it's like it was never there. Easiest solution to the most annoying problem ever. The bottle should last awhile as you dont need much to get results. Worth every penny.

Best algae control product on the market--at least that I have found. Almost gave up my aquarium because couldn't keep the algae down; plants were dying. Daily use of this product stops it in its tracks.

Didn’t really notice a difference