Frequently Asked Questions

Q: Will these products harm fish?

A: Read Cutrine-Plus and Hydrothol 191 Granular labels carefully regarding fish cautions. Fish are generally at greatest risk from oxygen depletion resulting from rapid decay of dead vegetation.

Q: Can I treat my entire pond?

A: Best results are achieved by treating an entire pond. This reduces the likelihood that untreated areas will encroach on treated areas. Treatment of an entire pond should be done in sections. Treat one third to one half at a time and allow five to seven days between treatments. This will reduce the possibility of fish suffocation due to oxygen depletion from decomposition of dead weeds. This is of greatest concern in warm waters when using rapid-acting contact herbicides and algaecides on well developed weeds and algae.

Q: When should I apply aquatic herbicides?

A: As a general rule, these products should be applied when weeds are actively growing. Controlling aquatic weeds usually requires more effort as the season progresses and weeds become well established. As weeds mature, growth slows and systemic herbicides become less efficient. Mature weeds may hinder access to the treatment site and when treatment is done, a greater amount of dead vegetation will result.

Q: Which product works best?

A: Each product works best in different situations. The best product for a given weed depends on several factors, the type of weed, time of year, intended water uses, depth and area to treated. Call us at 1-800-328-9350 for help in determining the best product for your situation.

Q: How long will a treatment last?

A: The length of control will depend on the product used, weed(s) treated and local conditions. Systemic herbicides will provide longer term results than contact herbicides. Slow growing weeds will take longer to re-develop than rapidly growing weeds. Treating an entire body of water will provide longer term control than treating a small section of a larger body of water.

Q: What are systemic and contact herbicides?

A: Systemic herbicides are absorbed by weeds, move throughout the weed and kill the entire weed including roots. Successful systemic treatments require consistent presence of herbicide for absorption and more time to work. Usually only one treatment per season is necessary. Contact herbicides kill only those parts of the weed which they touch. Contact herbicides begin to work quickly and require less time to show results. More than one treatment may be necessary for season long control with contact herbicides. 

Q: Why both granular and liquid products?

A: Granular products are used to control bottom growing or rooted weeds and algae. Liquid products are used to control weeds and algae which are at or near the surface or have easily accessible foliage. In many cases either form may be used successfully.

Q: Is mud a problem?

A: The effectiveness of chemical control is reduced in muddy or turbid waters. Liquid herbicides are not absorbed well by mud covered foliage. Clay, silt or mud will reduce the effectiveness of granular or pelletized herbicides. AquaClear Pellets or Clear-Pond Pellets will help solve these problems.

Q: Do I need a permit?

A: Control of weeds in state protected waters often requires a permit. Consult your State Fish and Game Agency before beginning any control operations.

Q: What water temperature is best?

A: Generally chemicals will be more highly active and effective at warmer temperatures. Warm temperatures also help insure active weed growth which is necessary for best results. If a specific temperature is recommended for use, it will be specified on the product label

Q: Don't fish need weeds to produce oxygen?

A: Weeds do produce oxygen, but not nearly as much as is stirred into the water from the atmosphere by wind and wave action. Heavy surface mats of weeds and algae may actually reduce oxygen available to fish and other aquatic organisms by sealing the surface.