Nymphing Subtleties: Part 2

Guest Blogger: Joe Dellaria, Woodbury MN

In Part 1 of this series, we began looking at using a two-fly set-up where the lead fly is a dry fly of your choice with a dropper to a bead head nymph. We looked at how the types of dries, the dropper length and diameter, and the size and type of bead head influence how deep the nymph will run. In the second part, we will look at how the style of the fly influences the depth and how one can adjust the different variables to consistently tick the bottom. When you get all that right, this can be a very productive style of fishing.

Style of fly. I have found that color and type of fly often doesn’t make a big difference as long as you get the nymph down to the right depth. However, there are days where color or style can be important so don’t be shy about switching nymph styles if the bite is slow. The bigger issue is how fast do you want the nymph to fall and how deep do you need to be to get fish. This is where the style of the nymph plays a huge role. For faster sink rates and deeper water, I prefer using Copper John nymphs. They drop like a rock (especially when you drop your last one accidentally into the water). I use these in deeper or faster water. If you find that you are snagging too much with a Copper John you can either downsize one size or switch to a fly style that has a slower sink rate. For these situations I like Prince and Pheasant Tail nymphs. When I am facing shallower or slower water and I want a slower sink rate, I reach for my Hare’s Ear patterns in various colors. They sink the slowest as the fuzzy body style produces drag that reduces the sink rate.

How many tungsten head nymphs do you need? I am always trying to whittle down the number of fly boxes I carry and tungsten head flies are slightly more expensive. If you tie your own flies you will find that buying tungsten heads in every size you might use can get expensive (Also be ware, tungsten beads are actually partially steel. If you find some that are much cheaper, there’s a good chance they have less tungsten. This is one case where spending the extra money for high quality beads is probably worthwhile.).

Depending on the water you fish, it may make sense to have tungsten head nymphs from #18-#10. However, that gets pretty expensive and requires a large fly box. I find it most useful to have tungsten head nymphs in sizes #12 and #16 and carry the same styles in #14 brass bead heads. This covers 85% or more of the situations where tungsten heads have the biggest advantage. I keep the tungsten heads in a separate fly box to avoid the confusion that can arise when you mix brass and tungsten heads in the same box. All of these fit into a 3 ½ x 2 ½ x 1-inch double-sided fly box (I buy the plastic box empty and convert it to a fly box by fitting it with PSA backed foam.). I also find it helpful to add eyes to the tungsten heads to make it easy to distinguish them from their brass brethren. You can do this by applying white or pink fingernail polish with a toothpick.

Below I provide a picture of my tungsten head nymph box. You will note it is fairly small. I find this is enough to cover most situations without breaking the bank and carrying enough sizes for different situations. I list what is in each row of flies next to the picture.Depth charge flies. Last year a friend of mine and I fished one of my favorite spots with the “standard set-up.” We caught a couple of 13- and 14-inch browns on the edges and at the head of the pool but knew there were bigger fish to be had. Fortunately, I had tied a few #10 mini-girdle bugs with a tungsten head. We took turns running these through the hole we had just fished. My friend took the first cast and half-way through the drift he thought he had snagged the bottom. He was walking around trying to free the snag from different angles when an 18-19-inch beauty leapt out of the water and threw the fly in his face. We continued working the hole and got a 15- and 16-inch brown apiece. We did eventually snag the bottom after the fish quit biting. We now refer to #10 tungsten head mini-girdle bugs as our depth charge fly and reserve it for those really deep holes.

Tying flies on heavier hooks. Recently, I have started tying girdle bugs on a heavy hook for very low water situations and/or in areas with slower flow rates. Daiichi 1530 hooks are 2X-heavy; they are a good value as they offer excellent quality at a price that won’t break the bank (other equivalents are: Dai-Riki 075; Mustad 3908; and Tiemco 3769). Sizes #8-#12 on a 5X fluorocarbon dropper will waft down the river just above the bottom when the dropper length is 1.3-times the depth of the water you are fishing. I have found this to be very productive in situations where the fish are holding in shallower cover during low water conditions in 12-24” of water. You will definitely get some snags, but most of the time you will see the lead dry fly hesitate slowly as the dropper starts dragging over the potential snag. If you give your rod tip a slight jostle it will pull the dry 3-4 inches and avoid the snag. The only trouble is near-snags and takes look nearly identical. If you feel any resistance when you do the jostle, set the hook, it is probably a fish.

Surprisingly, this works in up to 3-3 ½ feet deep water. Last summer I was using a #14 parachute Purple Haze and a #10 girdle bug on a 40-inch dropper. After a half hour of no takes, I made a cast into a deeper section and pulled out my fly box to pick out a different fly. I wasn’t paying attention to my line as I knew it wouldn’t get snagged in this run. I happened to glance at the water as my fly was floating by just off the bottom in three feet of water. To my amazement I watched a 14” brown casually coast up and take the fly about five feet from me. Fortunately, it was a relatively short cast so I slowly pulled in the slack and set the hook and landed the fish.

Observed Sink Rate for Different Flies. Nymphs, girdle bugs, and wooly buggers sink at different rates. Nymphs with slim bodies that are hard or sleek have the fastest sink rates. Copper John’s and lightning bugs are examples of this class. Next come nymphs with trim but softer body materials, these have a medium sink rate. Pheasant Tail and Prince nymphs are representative of this group. Finally, the slowest sinking flies have larger, soft, fuzzy bodies. Hare’s Ear, Cased Caddis nymphs, and wooly buggers are in this class.

Body materials can have a big influence on the sink rate. I have switched almost entirely to the Estaz (Glissen Gloss, # SM-710110-0000), Cactus (Hareline, # SM-700240-0000), or Pearl (e.g. Wapsi, # SM-700366-0000) style chenilles. These have a looser weave with harder material. I haven’t done an experiment to prove this, but by observation girdle bugs and wooly buggers with these bodies run deeper. You may want to keep some of the old fashioned chenilles for shallow water situations.

Here’s a quick reference guide for observed sink rates. You can extrapolate to other style flies to make a decent guess at their sink rates based on these.

Making adjustments until you catch fish. I put together a table for different ways you can adjust the variables to get your fly consistently ticking the bottom. Remember, this is mostly for low and slower flow situations. When you are facing high water and faster currents follow Michael Vorhis’ advice in his blog.

This is a trial-and-error process. Keep experimenting with the variables until you have success. Start with the “Standard Set-up” which uses a #12-#16 parachute dry of your preference. I tend to carry Adams and Purple Haze patterns in all three sizes. If a hatch has been coming off, use the closest pattern and size you have in your box. Determine the average depth you will be facing in the area you will be fishing and add ~1/3 of the depth to the length of your dropper. Use 5X fluorocarbon and a #16 tungsten head nymph. The table below will help guide you through adjustments you can make until you are ticking the bottom of the river regularly on each drift.


This is definitely a finesse style of fishing that requires some fiddling to get the set-up adjusted to the depth and speed of the water you are fishing. With enough practice you will develop a feel for where to start and how to adjust the dropper, bead head size, and style of fly pretty quickly. On most outings I get pretty close on the initial set-up and take 15-30 minutes to work out the adjustments until the nymph is ticking the bottom regularly. It is worth the effort to master this style of nymphing as it can be incredibly productive; especially when nothing else seems to be working!

5 thoughts on “Nymphing Subtleties: Part 2

    1. Joe Dellaria

      Hi Camper,
      Thanks. This really helps me change flies and adjust more quickly. It has really helped me catch more fish. Hope it helps. Let me know if you have any questions.
      All the best, Joe

      Reply
  1. Michael Vorhis

    Joe, truly an excellent discussion. I like especially how you emphasize the effect of fly type on its own sink rate. I’ve found that not only the width of the fly (which as you say creates profile drag that impedes its descent) matters, but the dubbing materials themselves. A soft-bodied subsurface fly needs to absorb water if it is to sink. The dubbing is always composed of tiny fibers of one kind or another. If those fibers are naturally hydrophobic, each of them creates a surface tension zone around itself, and it takes the water time to permeate through to the hook shank. Much of that water can also be easily shed again during a back-cast, requiring the process to repeat for every drift. The time it takes the water to permeate to the shank slows the sinking process. Natural fibers not coated with natural oils can sink more quickly and once “wetted” can sink faster on subsequent casts. Of course once they do they still suffer from the profile drag you mentioned.

    Enter the trusty spool of lead wire at the tying bench, to brute-force-solve it for any fly. : )

    (When I use lead wire, by the way, I then coat it with head cement to make it as inert and stream-safe as the lead substitute is. That may not address the letter of a law but it certainly adheres to the spirit.)

    Really enjoying your articles about this.

    – Mike

    Reply
    1. Joe Dellaria

      Hi Mike,
      Thanks! Hopefully it will increase your success rate. I know it has made a big difference for me. It helps me adjust to conditions more quickly.

      Elemental lead has zero solubility in water (see https://www.lenntech.com/periodic/water/lead/lead-and-water.htm). I really don’t understand the big whoo-hah about lead shot. The problem is not lead solubility but that animals ingest the lead. In a deep lake it is a non-issue. In shallow marshes, ducks ingest lead shot while eating – there’s where the problem lies. Lead only becomes soluble after a chemical reaction that is exceedingly slow in water.
      The lead from our flies has a near zero impact on lead concentrations in the streams. I know it is a hot topic – but if you look at it from a scientific point, it shouldn’t be such a big deal. Perhaps it makes people feel like they are doing something for the environment (which they are, it just doesn’t do much).
      Sorry for the diatribe. The scientist in me wants to help educate so we can work on problems that really need fixing!
      All the best, Joe

      Reply
      1. Michael Vorhis

        Yep, I know…regarding lead. A quick look at any battery terminal noting that the only stuff exposed is the inert compound lead oxide should be enough to convince folks…but alas not all. So I plastic-coat it with head cement so that I can later say I did. : )

        Again, a good article–definite food for thought. Thanks Joe.

        Reply

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