little white worms!?

I've been growing black mangroves from seed and there about 1.5 years old now. I've been growing hem in a clay/sand/mud loam and a none draining pot. Mangroves grow water so that's why a none draining. The last couple weeks I noticed little white worms- 1 cm maybe and they look like miniature earth worms. I thought ligustrumbe fungus gnats or whitefly but there is not a single gnats flying around? Any idea and how do I get rid of them without useing harsh chemicals? Don't thisnk ill be able to get a pic because my camera kinda sucks but ill try. Also I've not noticed any harm to my mangroves or drooping of leaves or discoloring

It is going to be a critter that thrives in very stagnant water.

Mangroves -- especially BLACK mangroves -- do not live naturally in stagnant water. They live in an environment where clean salt water mixes with clean fresh water and where it is changed twice a day by the tides or by tropical rainstorms.

I can't imagine that the plants are happy, even if they show no symptoms.

There is no standing water just very moist and gets fresh water and has been growing close to 3 inches a month. Trust me I've been growing Mangroves for a long time now and they are happy. I've just never had worms in the soil

If there are no drainage holes, and contaminants in the water you use -- or contaminants brought in by a foreign agent (dead insect, or what have you) are not going to be washed out of the pot. The soil/water eventually would have to be full of "stuff."