A Humidity Indicator Test Strip is included with every Dry-Tech MRT fly box in order to demonstrate the effects of the Moisture Reduction Technology design. Some very basic tests and observations can be made with a new box and just a few wet flies.

The strip indicates a range of humidity levels from 10%-60%. The more pink circles that appear on the scale, the higher the humidity level; the more blue circles on the scale, the dryer it is. You can disregard the danger statement printed on the strip. It is designed to protect sensitive electronic equipment.

Make sure that the pink or blue circles on the indicator strip do not come into direct contact with any water droplets, wet flies, or wet hands during the tests as this will permanently ruin the affected areas on the strip.

Test # 1

This test has 2 trials. The first trial will be done with the moisture absorbing MRT container inside the box, and an identical trial will follow after that with the MRT container removed from the fly box.

Trial 1

Soak 2-3 larger flies (size 12 wooley buggers for example), or 6-7 size 12 nymphs and separate them on a towel. Place the flies inside the box on one far side. Place the Humidity Strip inside the box on the other far side away from the wet flies and close the box.

Wait about 3 hours and open the box. During this time, try to avoid moving the box which might allow the humidity strip to come into contact with the wet flies.

Note the humidity level on the card. The strip should be completely blue reflecting a very dry humidity level at around 15% inside the box. This demonstrates that the crystals are regulating and maintaining this constant dry climate inside. It also reveals that the moisture from the drying fly is being completely absorbed by the MRT crystals without allowing any damaging moisture build-up to occur.

Trial 2

For the second part of the test, remove the MRT container from the foam. To remove the container, you can pry it up with your fingers or you can gently insert a small metal object to pry it up from the foam. Using the same procedure as in Trial 1, re-soak the same flies, and replace the flies and indicator strip inside the box in the same manner. Close the box and open it again after the same 3 hour period. You should observe a predominantly pink strip this time reflecting high moisture and humidity levels inside. This humidity will continue to climb and this level may remain for hours. You can observe this increase if you close the box now and reopen it again after another 2 hour period. These are the conditions under which hooks and tying materials will weaken and deteriorate. Larger freshwater and saltwater flies that retain greater amounts of water are even more adversely affected under these conditions.

Test # 2

Refer back to the humidity reading that you noted in trial 1. The completely blue strip should have reflected a 10%-15% humidity level inside the box. Now, obtain the actual relative humidity in your area from your local newspaper, phone, or online source. The humidity reading inside the airtight box should be considerably lower than the outside relative humidity. That means that while your flies are in storage in between fishing days or during extended off-season months, they will be maintained at a regulated lower humidity level. This would be even more significant if you reside in a high humidity saltwater climate since high outside humidity levels will contribute to the development of rust and corrosion.

Dry-Tech MRT

User's Guide

MRT Test Results