Rooted plants not doing so great

[Doug_E]

My Java Fern, anubias, and crypts(?) are all doing great. My other plants that are rooted (water sprite, val, and the foreground plant I can't ever remember) are not. I use Aquarium Co-op root tabs and liquid as directed. The rooted plants were doing great for a while. However not too long ago they just stopped growing as fast. The water sprite used to be so thick I had to trim it. The val was similarly fast growing with several shoots. Now the val has one small (3" tall) shoot left. The foreground plant is yellowish and has holes in the leaves. Even my dwarf water lettuce isn't doing as good as it used to. 

Is it some kind of mineral deficiency? SHould I use more root tabs and liquid?

My nitrate levels are 20-50 based on water changes. I have hard water (12) and pH8. The light is on 10 hours a day (fluval Plant at 30%). Substrate is Eco+ with Flourite black sand on top. Fish snails and shrimp are all doing well. 

[BaRanchik]

What is the temperature in your tank? How old are the tank and plants? What are you dosing exactly and how much?

Also, did you change anything since they were growing?

[Doug_E]

Temp is 68F

Tank is 6 months old

Plants were transplanted from a 20L that was about 5 months old, also at 66-68F.

4 pumps of liquid a week. 

New root tabs every 3 months. 

[Bentley Pascoe]

Depending on how you're dosing your fertilizer (and how much compared to size of tank) my first inclination here is those water sprite aren't getting enough nitrogen.

 

Here's an article from the Co-Op blog that can give you some extra details on telling plant healthy and associated issues: https://www.aquariumcoop.com/blogs/aquarium/plant-nutrient-deficiencies?_pos=1&_sid=42bd4337f&_ss=r

 

Personally, I try to space my fertilizer usage out.  So if I'm going to dose a 40g Breeder that is very dense in it's planting, I would dose something like 1 pump of easy green per day rather than 4 pumps twice per week.  This keeps a continuous lean source of nutrients in my water which helps plants consistently grow and remain robust.  You can of course adjust this if you use CO2 or find it to be not enough when testing your water.  The goal is to have a semi-constant 10-20ppm nitrate in the water at all times, this means there is constantly something for the plants to use.

 

It takes a little time to get used to it, but once you get in the habit and dial it in, you'll never go back.