Dwindling java fern/ need to grow algae

[LuckyScales]

hi im not new to the hobby but was wondering why my java fern is alive but slowly getting smaller through time. Let me tell you about my tank.
i started the cycle early in January of 2018 its a 20 gallon tank with the same filter it has came with (Tetra whisper ) and the ph is 7 to 7.4 i think and i have a bunch of fish 20 guppies 5 neons 3 red eyed tetras 2 red tail sharks a goldfish ( i can all ready see the eyerolls) Didnt mean to keep the goldfish my turtle wouldn't eat him. and one common pleco 6in ( i know he will get big i plan on putting him in my 40 gal turtle tank) i do water changes once a month because my ammonia is never a issue its always in safe or ideal area i do once bi monthly deep cleanings 50% water change cleaning filter and sand and adding more beneficial bacteria. The LED light that came with it got water in it and i didn't trust it anymore so i had it in front of my window for a few weeks but my room never gets much sun so today i added a soft yellow LED to hopefully grow some algae for my pleco but along with all this my java ferns get smaller and smaller leaves and I'm worried its gonna die out

 

[Ktownmatt]

Your cycling and water changes might be affecting the Java Fern (and are almost definitely affecting your fish).
With that many fish in a 20Gal, you should probably be doing water changes weekly. Probably 25% or so.
Your ammonia SHOULD be 0 all the time. What are your nitrates testing at? That'll tell you when you need to do a water change (usually >20ppm).
When you do a "deep cleaning," how are you cleaning the filter? The best practice seems to be that you squeeze the sponge out in a bucket of the old dirty water (this keeps the bacteria consistent). I wouldn't bother cleaning the other filter components.
You shouldn't need to add more Beneficial Bacteria once your tank is cycled. If you're needing to do it now, i suspect you're doing something to the filter media that's forcing a restart every time.
As for the lighting, I suspect that it's not enough for the Java Fern even though they're pretty easy to support. Without a strong overhead light source, I'd expect almost any plant to wither.

 

[LuckyScales]

yea i dont feed my fish every day i feed the amount of 25 seconds for the fish to eat the food every other day and feed live brine twice a week. When I do water changes and deep cleanings i use the water I take out and rinse the sponges in that I plan on buying a master test kit but my test just say ideal which is 0 safe under 5 stress under 10 and danger 10 and above ppm and I use seachem stability and it says put some in once a month to keep the cycle going strong
but all my tests say either safe or ideal but right before I do change the water the nitrates and nitrites are borderline stress I plan on giving my goldfish to my teacher because she has a 40 gal goldfish tank with two comets. Also when I deep clean the filter I never touch the bio media I put it in a separate bowl with the tank water and I rinse all filter parts.
well its pretty bright it makes the tank so bright I can leave my room light off. I'm going to go buy some seachem flourish and see if that helps.


Im open to constructive criticism so please let me know if I need to change any habits and I will start to do more water changes

 

[Aiken Drum]

First off, can you confirm that your java fern isnt planted in the substrate. If it is, that's your problem.

Your troubles with your plants started when your light failed. The soft yellow light of your new light might not be great for plants. Plants really need the blue and red ends of the spectrum, which tends to come from a white light. Look for a light fiiting that gives out 10 to 20 lumens per litre of tank and a colour temperature of 5500 to 8000 kelvins.

Let us know what your nitrate is when you get the numbers. With that large a stocking and the infrequent water changes i would be surprised if they arent high.

 

[LuckyScales]

First off, can you confirm that your java fern isnt planted in the substrate. If it is, that's your problem.

Your troubles with your plants started when your light failed. The soft yellow light of your new light might not be great for plants. Plants really need the blue and red ends of the spectrum, which tends to come from a white light. Look for a light fiiting that gives out 10 to 20 lumens per litre of tank and a colour temperature of 5500 to 8000 kelvins.

Let us know what your nitrate is when you get the numbers. With that large a stocking and the infrequent water changes i would be surprised if they arent high.

no they just float around. My tank is also in front of my window to get some more natural light. But I will look into that light I just have a low budget because I cant work much since I'm in school