# Frogbit dying in one tank but not the other



## maverickfish (May 19, 2019)

I recently ordered some amazon frogbit from Ebay. I've had it for nine days now. I have two five gallon tanks, which are almost identical. They both house a Male betta, one merits snail, have the same heater, and the same filter. 

When the frogbit arrived, I divided it between the two tanks pretty evenly. All of it was green and healthy looking. Now, in tank A, the frogbit has developed roots that are three or four inches long. In tank B, most of the frogbit has turned brown and mushy so I pulled it out.

Both tanks have the same water and are cleaned the same day each week, both with a 20ish% water change. Both get equal amounts of light. The only difference I can think of is that tank A is being treated with melafix (contraversial with bettas sometimes, I know) and tank B isn't. Could this be the reason that the frogbit is doing so well in one tank, but is completely dying out in the other? Is there anything I can do to save my frogbit, or help frogbit I buy in the future?

Thanks in advance for any feedback!


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## mysiak (Jan 17, 2018)

Could you post photos of both tanks? In my experience, frogbit and other floating plants die when:
1. air above water is too humid - when there is a condensation on the tank cover, it's too much
2. splashing water with drops on leaves - caused by an air stone, filter output etc.
3. too strong water movement - plants are pushed around the tank or under water
4. low nutrients, especially nitrate and iron


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## maverickfish (May 19, 2019)

Tank A














Tank B














There is some condensation on both hoods, but not enough to drip down, it's just a fine layer of moisture. What fertilizer would be best to use for the frogbit? I have root tabs for my other plants, but I assume those won't help my frogbit any.

Edit: Granite (the fish in tank B) does keep creating bubble nests around the frogbit. Could that be causing problems?


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## mistergreen (Mar 3, 2007)

You can buy aquarium plant fertilizer you add to the water at the fish store. They need ferts in the water, not in the substrate.


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## hoppycalif (Apr 7, 2005)

mistergreen said:


> You can buy aquarium plant fertilizer you add to the water at the fish store. They need ferts in the water, not in the substrate.


Why would only one tank have the problem? The most obvious difference between the tanks is the Melafix, even though the manufacturer says it has no effect on plants. I have never used it, so I have no evidence that it does affect plants.


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## mysiak (Jan 17, 2018)

maverickfish said:


> Tank A
> View attachment 61983
> View attachment 61985
> 
> ...


I see two problems:
1. Plants being pushed down under water, this will slowly kill them. Try to make some divider (for example from air tubing or fishing line) to keep them away from the falling water. 
2. Based on the yellowing leaves I suspect lack of nutrients in the water, most probably nitrate, iron or both. For nitrate you do not need a fertilizer, just feed a little bit more than usual (but verify your levels before doing it). For iron you'll need a fertilizer, Seachem flourish for example, even though it might be tricky to dose it in such a small tank as it's very concentrated.


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## maverickfish (May 19, 2019)

I used some airline tubing and suction cups to "rope off" the front of the filter. For some reason that filter seems to have more oomph to it than the other filter. Would switching to a mesh lid help as well? Or is a bit of condensation okay?


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## mysiak (Jan 17, 2018)

Mesh lid would certainly help to keep air above water fresh and not too humid, but I am not sure how will your bettas react to this. They need warm and humid air for breathing to not to damage the labyrinth organ. Could you maybe lift the existing lid just a bit? Even 1mm gap is sometimes enough for a good air exchange. I would say that condensation on its own doesn't cause issues to the plants, but it's a good indicator of too humid air which can damage their leaves. Pistia and Salvia are especially vulnerable to this, Frogbit and Red root floater to a lesser extent.

In each case I would start with fixing the splashing and nutrient deficiency issues, maybe it will be the only change you need.


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