how long does tank spray mix last


We are looking at Neem.  Once we mix up a gallon, how long will it remain good in the mixed solution?

This is a great question and one we get quite often. To best understand the answer it’s important to understand the difference between “ready to use” products versus concentrates like we sell.

For starters, ready-to-use sprays don’t need to be mixed; they usually come in a spray jug or bottle and can be used immediately as is. Concentrates will require mixing. In most cases water will be the “carrier” but many concentrates can be mixed with deodorized oil. Ready-to-use sprays are very dilute and to keep them in this form they require a lot of stabilizers. These additives insure the active ingredients don’t break down so that over time the spray will remain intact as long as the product is stored at room temperature and out of direct sunlight. Concentrates cannot be used this way. Once mixed, they’ll be vulnerable to rapid depreciation in their sprayable form. In other words, where sprayed they can last weeks or even months because this is how they were designed to be used. But these areas will quickly dry and assuming they’re protected, the active ingredient can persist. In general, it won’t do nearly as well if stored in water because the active isn’t meant to be kept this way. But this is by design and not a shortcoming. Let me further explain.

One of the big “drawbacks” of any ready-to-use spray is that it has all kinds of toxic additives. Referred to as “solvents, stabilizers or suspension agents”, in many cases these additives are more hazardous compared to the active ingredient! Additionally these very same additives can many times smell strong, burn plants or stain surfaces where sprayed and in general cause a lot more problems then they’re worth. On the other hand concentrates mixed with water will be as close to pure as possible and many times won’t have any odor or chance of staining. This would be one of their advantages. Additionally, it’s always nice knowing every time you need to spray you can have a “fresh” batch of product made for the job at hand. No doubt storing a ready-to-use spray over time will have a negative impact on just how much active ingredient is actually in the spray the next time you go to use it.

Another problem with the ready-to-spray formulations is that the stabilizers don’t actually do their job that well.. Many times they’ll actually break the active down when kept in storage and this can be to the point where the active is barely detectable or useful anymore. Unfortunately there is no practical way to guage or test how much active might be left in any spray so in the end, you can very well buy a product that is already in it’s “useless” range. To avoid this problem, the use of concentrates is the way to go and the only products we sell.

Of course, the big drawback of the concentrates we sell is that you need to mix them up. This does require a little effort and some precise measurement to make the finished spray just right, but fortunately the advent of small easy to pour “tip’n measure” containers are in use. They’ve made it easy to get exact measurements out of the container and into your spray tank. But another short coming is that the finished spray mixed won’t last long in the spray tank. In general, it might be good for 1-2 days but don’t store it any longer. Some concentrates might coagulate which can clog a sprayer. Others will simply loose their strength and won’t work when applied. But again, they don’t have all those “extra” ingredients the ready-to-use have so this is to be expected and not something we try to hide. In fact, it’s something we embrace. Here’s why.

If you have a vegetable garden you want to spray but are unsure of how much to mix, don’t make an entire gallon to start. Instead, mix up just 1/2 gallon. After treating the given area a time or two you should know exactly how much you’ll need and from then on, make only that exact amount. It might turn out to be just 1/2 or maybe 3/4’s of a gallon. Regardless, any of the sprayers and concentrates we carry including the NEEM can be mixed to a specific amount of finished product. And it’s quite common for people to only mix as little as a quart at a time for small applications so this is perfectly normal to do. In the end, using up what you mix the same day is the best way to go and definitely what we recommend.

Hopefully this answers your question and if you need some help determining how much concentrate you’ll need to add to get the finished amount needed for your target site, give us a call toll free at 1-800-877-7290 and one of our reps will be able to assist.

Here are direct links to the information and products listed above:

Neem Garden Spray Concentrate:

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