# Fuzz Algae and stems drooping



## art_b (Sep 2, 2006)

Recently my rainbowfishes have taken fancy of my hygrophila polysperma and were taking a nibble of the leaves. I now feed them green and vegetable matter, but still could not stop them from eating the polysperma completely.

I notice that the polysperma stems droops when reaching near the surface of water, and the top leaves of the plants (including other plants) start to have fuzz algae. The algae are fine green hairs growing on the leaves.

I can accept the reality that my fishes will eat my plants, and just hope the the fast growing polyperma would compensate for the loss. But I'm in a dilemma of whether to increase or decrease my ferts. I used Seachem Flourish and Flourish Excel. I don't have CO2. I try to keep NO3 at around 10 ppm and PO4 between 1-2 ppm. I started decreasing Flourish last week but not sure whether it is the right thing to do. I heard that fuzz algae is cause by nutrient deficiency, but I'm not sure whether it is more related to my rainbowfishes nibbling my polysperma.

Please help. Should I increase or increase my ferts.


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## hoppycalif (Apr 7, 2005)

How much light do you have, and how big is the tank? Light, more than anything else, is what drives algae to grow. If you have high light intensity you usually need CO2 to avoid constant battles with algae. Excel can substitute for CO2 to some extent, but too much light with Excel and you will still have algae.

One thing a lot of us have done is to reduce the time our lights are on to 6 - 8 hours, and that seems to help avoid algae too.


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## art_b (Sep 2, 2006)

I have two strips of T5 34 inch lights with a total of 78 watts. My tank dimension is 36 in x 18 in x 18 in. I keep the lights on for 10 hrs each day.


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## hoppycalif (Apr 7, 2005)

With T5 lights you have enough light that CO2 would be very desirable, in my opinion. And, you certainly need to fertilize adequately with that much light. What do you dose for nitrates, phosphates and potassium? You could use Flourish nitrogen, F. potassium, and F. phosphates, but that can get expensive.


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## art_b (Sep 2, 2006)

Yes, Flourish NPK can be quite expensive. I bought bulk from our local hydroponic shop of KN03, KH2PO4, and K2S04.


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## prBrianpr (Nov 18, 2007)

Co2!!!


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## FilteredFun (May 13, 2008)

Can I conclude that the suggestion to add Co2 to his equation is predicated on the formula that strong, healthy plants somehow deter algae growth?

Why exactly is this?

And, how many gallons equates to his 36"x18"x18" dimensions?

Thanks,
Matt


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## Adragontattoo (Jun 3, 2007)

50br or right around it.

Co2 gives the plants more Carbon to work with to grow in absolute basics.


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## hoppycalif (Apr 7, 2005)

It appears that having lots of plants growing well deters algae by using up the ammonia that fish leave behind with their droppings, etc. and that rotting plant debris generates. Since algae appear to treat a spike in ammonia as an invitation to start growing, keeping the spikes from ever showing up deters the algae. Whatever the reason is, it seems to work well.


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