Floating plants not growing

I'm having trouble getting floating plants to grow. I have Pearlweed that hasn't grown since I got it a month ago and I even tried duckweed. Still nothing. I double dose fertilizer everyday to keep up with the other plants in the tank. Is it time to thin out my plants? Do I need to stock my tank more to have more food for the floaters? What am I doing wrong here? I have 2 female guppies and 5 platies in the 29 gal tank with a 60 gallon sponge filter. Along with 15 fry in the breeder box, a ton of ramshorns, about 30 shrimp, and scuds in the substrate. I recently separated about 20 older fry from this tank because my ammonia alert was showing some ammonia. Should I put them back to help build nitrate levels? I thought duckweed was supposed to be hard not to grow in every tank you have lol

 

How strong is your current? Have you tested your nitrates? Floating plants love slow to almost still water flow at the surface and nitrates. Yes they need all the same ferts as any other plant but consume the heck out of nitrates.

 

The current isn’t very strong. It bubbles the surface but only in the tank of the tank and it’s a pretty slow bubble. Last time I tested them, they were around 40ppm. I added carbon and zeolite to media cups on the sponge filter to help bring it down, even though none of the fish seemed to be having an issue. I took it out about 3 weeks ago to dose the tank and haven’t added it back so the nitrates are probably back up. I’ll check it again tonight.

 

Hmm that's weird. I'm assuming it is not the light either as you're growing other plants in the tank. Your fish aren't eating them are they?

 

Not that I've seen. My fish have been boycotting flakes because they don't like eating from the surface so I doubt they'd go up to eat the floating plants. I have a nicrew skyled light on the tank and it runs for about 12 hours a day, sometimes more. Now that I think about it, I haven't been able to get duckweed to grow in any of my tanks, even my higher light that has a Nicrew BrightLed light on it.

 

It could possibly be something with the light. It is really hard to say. Duckweed and frogbit both usually grow like weeds but the light issue wouldn't make sense due to you having other plants growing fine unless it is too bright.

 

Can't say much about the pearlweed, but if your duckweed doesn't take up it is very likely a too strong surface current.

Can you post a picture of the tank? Often things suddenly make sense when one sees the tank in question.