As the others have stated, using coagulants like alum or ferric can be tricky due to the lowering of the pH and the reduction of alkalinity. Since you are in East Texas, you can bet you have low buffered, low pH water with lots of organics. The organics such as tannic acid and lignin from decaying leaves is a natural dispersant. This tends to help keep solids dispersed and prevents settling. In order to clear the water you need to first make sure you do not have a run off source that is bringing in new solids every time it rains. If you do, then you will need to correct this. Next look for areas along the bank that could be giving you wind erosion solids addition. Once you correct any source of new solids entering the pond, then you can try some of the coagulants to settle the solids. Aluminum salts work the best. Alum will lower the pH and in your case you likely already have low pH. Sodium aluminate will raise pH and will also work. In low buffered water you can go too high very quickly due to the sodium content and the dissociated caustic soda that is formed from the reaction. Poly aluminum chloride (PAC) will not impact pH, works great, works at lower dosage, is liquid so it is easier to feed, but is more expensive. Same for Aluminum Chlorhydrate (ACH). both of these can be purchased from an industrial chemical supplier Give me a call and I can help you locate one in your area if you have problems finding one.
Lastly, I mentioned the organics acting as dispersants. East Texas is very prone to this and usually has some heavy stained waters looking like tea. If you can reduce the amount of rotting leaves and pine straw you get in the water, you will help reduce problems all the way around.
