You probably need to determine the iron content first, before determining your optimal solutions. Moderate levels of iron should not hurt the fish or humans.

Does Texas post the water analysis for some of the water wells in the state records? (Some states do.) If so, examine some of the adjacent wells. If not, can you ask a neighbor with a water well for a copy of their analysis? Or offer to run an analysis for them?

Dissolved iron really wants to drop out of the water if you can get the water well oxygenated. Just a cascade through gravel-filled buckets would capture a lot of iron.

If you truly need to filter out a heavy iron content, research things like a manganese greensand oxidizing filter. They are not that expensive to run.

Good luck on keeping your pond water high and clean!