Can I plant spring flowers in June/July?
Are you referring to Spring bulbs?
In most circumstances, bulbs should be planting in the fall.
Here is a link with more information.
https://www.gardeningknowhow.com/ornamental/bulbs/bgen/spring-flowering-bulbs.htm
18 U.S. Code § 46.Transportation of water hyacinths (a)Whoever knowingly delivers or receives for transportation, or transports, in interstate commerce, alligator grass (alternanthera philoxeroides), or water chestnut plants (trapa natans) or water hyacinth plants (eichhornia crassipes) or the seeds of such grass or plants; or (b)Whoever knowingly sells, purchases, barters, exchanges, gives, or receives any grass, plant, or seed which has been transported in violation of subsection (a); or (c)Whoever knowingly delivers or receives for transportation, or transports, in interstate commerce, an advertisement, to sell, purchase, barter, exchange, give, or receive alligator grass or water chestnut plants or water hyacinth plants or the seeds of such grass or plants— Shall be fined under this title, or imprisoned not more than six months, or both. (Added Aug. 1, 1956, ch. 825, § 1, 70 Stat. 797; amended Pub. L. 103–322, title XXXIII, § 330016(1)(G), Sept. 13, 1994, 108 Stat. 2147.) Penalties - up to 6 months in jail and up to $5,000 fine.
Just no flowers. I have lots of fish for food
There may be too much nitrogen in the water, which may need to be adjusted. Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/watering/testing-water-for-plants.htm
https://www.gardeningknowhow.com/ornamental/water-plants/water-hyacinth/growing-water-hyacinth.htm