Mr. Saltwater Tank

Terrible Advice Tuesdays (T.A.Tues): Algae And This Food Go Hand in Hand?

Terrible Advice Tuesdays: Flaked fish food will cause algae problems in your tank.

The rest of the story: Poor flaked fish food. What a unwarranted bad reputation.

Here’s the facts: Any fish food can cause algae problems in your tank. However, the moment flaked food enters your tank, your tank isn’t doomed for an algae outbreak.

Therefore, don’t ditch that flaked food. Instead, only feed enough that your fish will eat quickly (before any hits the sand bed). I also recommend holding the flaked food under the surface of the water for a couple of seconds so that it stays submerged as some fish won’t eat food off the surface of the water. For example, my clownfish, firefish, anthias, and gobies won’t touch food that isn’t submerged.

Note that I’m NOT saying that fish food WILL cause algae problems. The misuse of any fish food can lead to algae popping up in your tank, not just flaked food.


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Comments for this article (22)

  • shaun, UK says:

    Agreed, this is when nassaruis snails come in handy, great snails and funny to watch, jumps out of the sandbed, has a snorkel and when it smells food in translation to them is “Bundles!”

  • Dave says:

    To much of any food will lead to higher phosphates and I turn algae over time.

    Keep up the great advice Mark.

  • Tony V says:

    Well my clownfish poke their little heads out of the water to be the first to get first bids on the food and they have taken food from the serface but the pellet foid sinks fast, oh and if they see the plastic spoon with shrimp oh boy they want to come out of the water. Good point Mark. Thanks!!

  • Frank says:

    I find this site educational and quite well done but the annoying pop ups to buy your books. If people want to buy your books they will know how to do so please re-think the annoying pop ups.

  • Frank…the pop over isn’t about buying any books. Thanks for the feedback though.

  • Matt says:

    Frank those books are full of valuable info that you won’t get from your LFS.
    They have helped guide me through many phases of the hobby.

    Also…. Mark doesn’t make a living and feed his family by dispensing free info and posting info everyday;)

    Keep up the good work Mark!!

  • Matt says:

    Good to see another Matt about with obvious intellect 😀

    The part about placing the flake under the water level is invaluable… Most of us won’t switch the return pump off (for those of us with sumps) and as a result the majority of flake on the surface will quickly find it’s way down the pipework. My fish are mostly tame enough to feed from hand… In fact stopping the bullies eating the lot is the main issue for me!

  • Lisa says:

    Hi Mark,
    I like the variety of flake products available and use many from Brine Shrimp Direct. I also use their Golden Pearls. However, as you stated, I feed very sparingly. Also, I never put directly into tank, I put in a plastic measuring cup and add water, then I pour into tank. There is never any floating on the top and straight into the overflow. The fish seem to appreciate this as well.

  • nathan says:

    I love flake food cause what the fish and other inverts don’t eat in my DT will go into my very large 120 gal filtration system and feed everything in there. I love the stuff.

  • Mike says:


    Thanks for another solid topic. Yes knowing fish and their feeding behaviors in combination with the “No Flake/Food Left Behind” rule is a great way to stay away from Nitrate and phosphate build up and

  • Mike says:

    And nothing else that was it. ;o)

  • CN says:

    I have been feeding the only fish in my nano, a bicolor Dottyback, 3 mysis shrimp only, daily, for three years. He has grown from 1″ to 2-1/2″, is a holy terror, and simply is not interested in more food than that. I think most fish don’t need as much food as some think they do.

  • jack says:

    Mark, please keep advertising your books and monetizing your site, via popup or whatever method works best. I am glad that you have found a successful way to monetize your love for reef keeping, and I am thankful for the free content you provide.

  • english steve says:

    All I feed is dried food except to the anemones. If you have enough turbulence on the water surface the flakes get swept under the water instantly as you put the food in

  • Shawn says:

    I always got frustated when feeding my fish and watching half the food get sucked into my overflow. I fixed this by putting my vacuum tube in the tank and putting the food in it. Once the food sinks it comes out mid tank level and the fish love it. Plus I’m able to target different corals at the same time. Its fun to watch hermits try to climb up the tube trying to get first dibs also.

    Thanks for all you do Mark!

  • Laurie Coleman says:

    Hi Mark
    Thanks for that snippet of information, is it also true that your pumps should be switched off while you are feeding.
    keep up the good work.

  • Richard says:

    Regards to flake food… I got hold of some 1/2 inch irrigation tubing, cut into 4 pieces to make a rectangle a dn then joined with 90 degree bends, all available in your local hardware.
    This makes a floating coral for flake food and as it absorbs waer it then sinks rather than going into overflow and sump.
    I hold in in position with a little sucker thing and this keeps it in place under my auto fish feeder. It’s vital for me as I travel away for sometimes weeks at a time.
    My fish and tank are all in good shape…:-) Great info Mark, thanks.

  • Dave says:


    That’s a really neat idea! I will have to remember that for my next vacation.

  • David says:

    Along same lines but off subject is it worthwhile to use a UV Sterilizer to combat algae?? Thanks

  • railcar says:

    I still don’t care for flake. And I agree the pops are annoying. He does tank consultation. Reviews, tank builds for clients, the books are a bonus, but I would rather not get plastered with popups. I bought a book once, and was disappointed.

  • Dreadedlurgi says:

    Railcar you are an idiot! Why not go to another site rather than whinge here?

  • Laurie Coleman says:

    I cannot think of many people that would give up their time to try and educate others.
    The majority of subscribers to Mark’s “Mr Saltwater tank” web page enjoy reading and being taught from him in this manner, so please keep your opinions to yourself and stop trying to kill the golden goose.

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