Rowa carbon amount to use


Dear Sir/Madam,

I am Colin Maniscalco from the island of Malta.

I proudly use for years now Rowa Phos and Rowa Carbon in to my reef aquarium. They are excellent. I believe that both products are the best that an aquarist can buy. But sometimes people don’t give you the right amount how many the product threats in water. I’ m writing this e-mail just to confirm or give me the right answer how much Rowa Carbon threats per grams in liters, because I’ve been all these years in doubt and I want to know the right answer. Please can you tell me 500g of Rowa Carbon how much salt water threat? I own a 400 liter tank. I have a second question, where does Rowa Carbon works the best in a external powerful filter ( 1800 L/H ) or in a slower filter (1000 L/H ) ? The third question is how long should you leave it working for bestperformance? The fourth question is when you change the old one that has been working for ? days, you put immediately the new one or leave it for some time and then replace it?

Thanks a lot. Excuse me for my English because it’s my second language. Whilst waiting to reply me, I appreciate a lot your co- operation and for your excellent products.

Best Regards,



Thanks for your email.
Unlike Rowaphos where there are clear reasons and quantities for use, carbon is a much more difficult question.
Some people use carbon permanently, some use it only a few days per month and the variations are endless – see this poll which I pulled from the internet.
It depends on what you are using the carbon for as to how you would use it and so I have picked randomly a couple of articles again from the internet however there are thousands more and thousands of different opinions when it comes to carbon.
Generally most activated carbon does the same job however the issues with cheap carbon is that the final stage of production is to wash in phosphoric acid and so it releases phosphate into the water. This is where RowaCarbon, as a quality carbon ,is different as it releases very little phosphate into the water.
How long the carbon lasts will depend on the amount of yellowing or toxins in your tank and so it is hard to give you a recommendation.
People fall into 2 camps
1 – those who put some carbon on to remove yellowing and remove it after 3 days and throw it away. You can play with the quantities that satisfactorily remove the yellowing in your tank and add more if you need it.
2 – those who put an amount on the tank continuously and change it every month.
This is generally done blindly and results in questions like yours enquiring about how often to use it or to change it. The answer is I do not know as it will change from tank to tank and for this reason the first method is probably the best way.
I know this does not really answer your question however there is no real answer available