1) Don't Settle For Chocolate Milk: If you are trying to catch carp in really muddy water and having difficulty, the first step may be to look for the clearest water you can find. That may sound like a cop-out, and it is to a certain degree, but bear with me for a bit.
The first thing to realize is that if you are fishing big water, water clarity can vary dramatically in the same body of water. The location of the inlet, the wind direction, local vegetation and local bottom composition all change local water clarity to a certain degree. If you spend the time to explore your water and pay close attention I think you will be surprised how different the next bay over can be.
The second thing to realize is that in many parts of the country the next carp pond is just a bike ride away. Be sure you have exhausted your options before resigning yourself to fighting the good fight.
That being said you may legitimately have no recourse. If all you have access to is dirty water, that is all you have. All is not lost!
2) Fly Color: In dirty water I tend to prefer black flies. Or black. I hear black works as well. It turns out that if there is any light penetration at all the color black is one of the easiest colors for carp to see in dirty water because it creates contrast.
Surprisingly enough (to me at least), egg yarn colors also seem to also do well. I don't know if that is because they are bright or typically include fluorescent UV effects but I know of quite a few carpers that do very very well with brightly colored egg patterns in turbid water.
3) Lighten Up Man: Generally the cloudier the water, the more likely I am to fish a lighter fly. I have found that in low visibility it helps if you fly doesn't plummet for the bottom because it gives the fish more time to notice the fly mid-column when it has a chance of creating a contrasting profile.
4) Flash Dance: I used to use a bit of flash in my flies if I was expecting dirty water, and in general I think it helps a bit. I don't as much any more because I can usually find clear water at some point in the day and want my flies to work there as well - and there is nothing worse in clear water than anything but subtle micro flash in your carp flies. For a long time a black backstabber with an olive body with significant flash in the dubbing was my go-to fly in dirty water.
5) Shallow Hal: Be sure and check the shallowest water available in your water first thing every time you go. Carp are actually extremely light sensitive, and they tend to be more willing to feed shallow if turbidity shields them from the sun. As a result, in very dirty water you are much more likely to find them with their tails, or even backs, out of the water. If carp are feeding in 6" of water you can almost always see them and they can almost always see your fly. Also, your odds of finding super shallow carp go up if water levels are rising or high rather than dropping or low.
6) The Suspense is Killin' Em: IF you can find the fish tailing shallow enough that you can find them and IF you can sneak up close enough to dap them, the suspended dap is absolutely deadly in turbid water. In the suspended dap you hold the fly under your rod-tip just a few inches off the bottom near the head of a tailing carp. This insures that the fish has the best chance of detecting your fly and works so good. Ohhhhhhhhhh so good! And yes, it would seem to follow that suspending your flies just a smidge off the bottom with and indicator would work......I just haven't tried it, but that brings us to:
7) Indicate This: I know of several experienced capers who catch allot of fish in cloudy stillwaters using indicators. Some of them suspend the fly. Some of them put it on the bottom. The key is that even when you do find the right carp in the right scenario in muddy water it can still be excruciatingly difficult to detect the take. An indicator can help! Another alternative is to watch your leader for any slight motion.
8) Set Early, Set Often: If you would prefer to skip the indicator and try and detect and time the take using whatever visible cues are available then I would advise that you should be liberal with your hook sets. The fundamental truth is that if you NEVER set the hook you will virtually NEVER catch a carp in dirty water so you better make sure you are setting the hook at the slightest hint of a take. All of the following (and anything else mildly suspicious) should be treated as a hint of a take:
- Speeding up or slowing down of tailing rhythm.
- A tailing fish who's tail suddenly disappears - It may seem like they have spooked, but they have often actually just leveled out in order to make a move on your fly.
- A change of direction while tailing or cruising.
- ANY change in speed while slow cruising.
You will foul hook a few more fish - and as we all know those don't count. I am sorry, it sucks, but I don't know how you avoid that if you have any real intention of catching a fish except for possibly using an indicator.
9) Subtle Cues: When trying to find carp in dirty water you often have to look for more subtle visual cues. Learning these cues can be a useful advanced skill in clear water too, but they are an absolute necessity in dirty water. These include:
- Tiny micro-wavelets in the surface caused by a carp feeding just under the surface. When you learn what too look for these tiny little wavelets can be visible from a shocking distance in calm water and are unmistakable.
- When carp feed on the bottom they often create a stream of bubbles because they liberate methane trapped in the bottom as they feed. In general you are looking for bubble streams that are erratic and move. The ones that are a steady stream of the exact same size in the exact same spot with the exact same rhythm over time are just little methane seeps.
- Even in extremely cloudy water you can usually detect subtle changes in clarity that indicate a carp, or several carp, are feeding in an area. When you detect that subtle change stop and take your time. Often a tail will become visible with enough patience.
10) Faith: As always my final piece of advice is to believe. If you don't believe that you can catch carp in dirty water you never will. Keep looking, keep learning and most of all keep trying. It will come.
Other resources: I have always liked this article on muddy water carping.