rig.type · bottom rigs
Fish Finder Rig
A sinker that slides on the mainline above a bead and a swivel, then a leader to the hook. A fish picks up the bait and swims off without feeling the weight. We ran it through the compatibility engine for 6 fish it is tied for: 6 of 6 clear every check. For Channel Catfish in Farm Pond the cheapest clean build is a 3/0 circle hook on 17 lb copolymer → 20 lb fluoro, 1/2 oz egg + barrel swivel, on a 6.6 ft M spinning rod. About $143.
tie it when
Bait on the bottom for fish that drop anything that pulls back: catfish, carp, redfish, stripers in the surf. The standard bottom rig.
skip it when
Rocky bottom with a heavy weight that wedges, and lure fishing. If the bait should move, this is the wrong rig.
How to tie a fish finder rig
- Thread the sinker or a sinker slide onto the mainline, then a bead.
- Tie the mainline to a barrel swivel. The swivel stops the sinker and keeps the bead off the knot.
- Tie 18 inches to 3 feet of leader to the swivel and a circle hook to the leader.
- Bait up, cast, and leave the rod in a holder with the line just tight. With a circle hook, do not set it: let the rod load and reel.
Solved for each fish
For every fish below, the solver searched the catalog at each water that fish is targeted in, under the rules in the next section, and kept the water where the fish finder rig scores best: fewest engine errors, then fewest warnings, then cheapest. Open any row in the studio to see the same verdict.
| Fish | Water | Hook | Line | Terminal | Rod | Approx. | Engine |
|---|---|---|---|---|---|---|---|
| Channel Catfish | Farm Pond | 3/0 circle | 17 lb copolymer → 20 lb fluoro | 1/2 oz egg + barrel swivel, natural bait | 6.6 ft M spinning | ~$143 | clears every checkstudio |
| Blue Catfish | Big River Channel | 7/0 circle | 30 lb copolymer → 50 lb fluoro | 1 1/2 oz egg + barrel swivel, natural bait | 10 ft MH surf | ~$373 | clears every checkstudio |
| Common Carp | Farm Pond | #1 circle | 12 lb copolymer → 15 lb fluoro | 1/2 oz egg + barrel swivel, natural bait | 6.6 ft M spinning | ~$143 | clears every checkstudio |
| Striped Bass | Inshore Flat | 5/0 circle | 20 lb copolymer → 30 lb fluoro | 1/2 oz egg + barrel swivel, natural bait | 6.6 ft M spinning | ~$220 | clears every checkstudio |
| Redfish | Inshore Flat | 4/0 circle | 17 lb copolymer → 20 lb fluoro | 1/2 oz egg + barrel swivel, natural bait | 6.6 ft M spinning | ~$220 | clears every checkstudio |
| Flounder | Inshore Flat | 3/0 circle | 12 lb mono → 20 lb fluoro | 1/2 oz egg + barrel swivel, natural bait | 6.6 ft M spinning | ~$219 | clears every checkstudio |
Every water each fish was tried in
- Channel CatfishFarm Pond (clears every check), Clear Reservoir (clears every check), River Run (clears every check), Big River Channel (clears every check)
- Blue CatfishClear Reservoir (clears every check), Big River Channel (clears every check)
- Common CarpFarm Pond (clears every check), Weedy Lake (clears every check), Clear Reservoir (clears every check), Big River Channel (clears every check)
- Striped BassClear Reservoir (clears every check), Big River Channel (clears every check), Open Surf Beach (clears every check), Inshore Flat (clears every check), Jetty & Pier (clears every check)
- RedfishOpen Surf Beach (clears every check), Inshore Flat (clears every check), Mangrove Estuary (clears every check), Jetty & Pier (clears every check)
- FlounderOpen Surf Beach (clears every check), Inshore Flat (clears every check), Mangrove Estuary (clears every check), Jetty & Pier (clears every check)
The water links go to the unconstrained rig for that pair, where the solver is free to pick any rig at all.
What makes it a fish finder rig
A named rig is a rule set, not a parts list. These are the rules we hand the solver. Every stage not listed (line test, hook size, rod, reel) is the solver's call, checked by the engine.
- weight.terminalrequired: egg or bank or pyramid, 0.5–8 oz
- bead.terminalrequired
- swivel.terminalrequired: barrel or ball-bearing
- leader.connectionrequired
- float.terminalnone
- lure.platformoptional: live-rig if used
The checks that decide it
The engine runs every check on every build. These are the ones that make or break a fish finder rig, with how many of the 6 solved builds each one still flags.
Sinker bore vs line0/6 flagged
A sliding sinker only slides if its bore clears the line through it by 0.15 mm. Under that it binds, and the fish feels the weight. The engine errors.
Bead bore vs line0/6 flagged
Same 0.15 mm clearance for the bead. A bead that binds stops the rig sliding and saws the line at the bore edge.
Weight vs current0/6 flagged
From a current rating of 0.5 the engine works out about 3 oz per unit of current to hold bottom, and warns under half of that. Float rigs skip it: they are not trying to hold.
Swivel rating vs mainline0/6 flagged
A swivel rated under the mainline test is the weakest part of the rig, and a hookset that breaks it takes everything below. The engine errors.
Circle hook technique0/6 flagged
A circle hook sets itself as the fish turns. The engine attaches a note: do not swing on the bite, let the rod load.
Cast weight vs rod maximum0/6 flagged
Past the top of the rod’s casting rating the engine warns, and errors 15% beyond it, where blanks break on a hard cast.
Every check on the Channel Catfish build
15 checks, each with what the build measures and what it is measured against. Lines for this rig's deciding checks are marked.
| Check | This build | Against | |
|---|---|---|---|
| pass | species.water | Farm Pond: fresh | Channel Catfish: fresh |
| pass | rod.reel.seat | spinning reel | spinning rod |
| pass | mainline.species | 17 lb | 15–30 lb window (warns over 45) |
| pass | mainline.rod | 0.4 mm ≈ 16 lb mono | rod rated 8–20 lb (under 4.8 warns) |
| pass | rod.power | M rod, rated to 20 lb | 15 lb fish (warns over 35 lb, fails over 50 lb) |
| pass | reel.capacity | ~254 yd of 17 lb copolymer | 200 yd for a 15 lb fish |
| pass | reel.drag | 13 lb max drag | 8 lb floor |
| pass | hook.size | 3/0 | 1/0 to 6/0 |
| pass | hook.strength | 70 lb before it opens | 18 lb (1.2 × 15 lb fish) |
| pass | leader.abrasion | 20 lb fluoro | abrasion 0.70: leader from 0.60 |
| pass | leader.ratio | 20 lb on 17 lb | 0.75× to 2× mainline (12.75–34 lb) |
| pass | weight.bore | 2 mm bore | 0.57 mm (0.42 mm line + 0.15) |
| pass | bead.bore | 2 mm bore | 0.57 mm |
| pass | cast.weight | 0.5 oz on the line | rod rated 0.25–0.625 oz |
| pass | weight.still | 0.5 oz | under 1 oz in still water |
Parts for the Channel Catfish build
Eagle Claw Lazer Sharp Circle Sea
The cheapest way to fish circle hooks correctly. Corner-of-the-mouth hookups, minimal gut-hooking, and priced so you re-tie without flinching.
Danielson Plastic Bead Assortment
Cheap, soft, and available in every size. The everyday spacer and knot protector: buy the big box once and stop thinking about it.
No exact product destination has been verified for this item.
Eagle Claw Barrel Swivel Assortment
A graduated box of brass barrel swivels. Perfectly adequate for freshwater bottom rigs and the cheapest way to learn what size you actually use.
No exact product destination has been verified for this item.
Bullet Weights Egg Sinkers
A rounded slip sinker for Carolina rigs and bait fishing. Line runs free through it, so a taking fish feels no weight before you come tight.
Verified destination: Egg Sinkers 1/2oz, 160 Each (2026-10-21).
Yo-Zuri HD Carbon Fluorocarbon Leader
Noticeably cheaper fluoro that still hides well and knots more easily than the premium stuff because it runs a touch softer.
Verified destination: 80 lb / 30 yd HD Carbon (2026-10-20). Other sizes or packs are not verified by this link.
Stren Original Copolymer
A blend that splits the difference: less stretch than straight mono, more manageable than fluoro, and cheap enough to respool often.
No exact product destination has been verified for this item.
Okuma Ceymar Spinning Reel
The floor for a reel that is actually worth owning. Smooth enough, a real drag, and light enough not to fatigue you on a full day.
Verified destination: Ceymar C-30 (2026-10-21). Other sizes or packs are not verified by this link.
Ugly Stik GX2 Spinning Rod
Effectively indestructible. A graphite-fiberglass blend that shrugs off car doors, tailgates, and everything a beginner will do to it.
Verified destination: GX2 6'6" Medium 2 pc (2026-10-21). Other sizes or packs are not verified by this link.
About $143 at street-price estimates from our catalog, not live Amazon prices. 0.5 oz on the line in total. Other fish need other parts: use the table above.
frequently asked
06What size hook for a fish finder rig?
It depends on the fish, not the rig. Across the 6 fish the engine solved, the hook runs #1–7/0: 3/0 for Channel Catfish, 7/0 for Blue Catfish, #1 for Common Carp, 5/0 for Striped Bass, 4/0 for Redfish, 3/0 for Flounder. Each size sits inside that fish's window on our hook size chart.
How much weight on a fish finder rig?
0.5–1.5 oz in the builds we solved, set by the water: 0.5 oz for Channel Catfish in Farm Pond, 1.5 oz for Blue Catfish in Big River Channel, 0.5 oz for Common Carp in Farm Pond, 0.5 oz for Striped Bass in Inshore Flat, 0.5 oz for Redfish in Inshore Flat, 0.5 oz for Flounder in Inshore Flat. The engine sizes it against current (it asks for weight to hold bottom from a current rating of 0.5) and against the rod's casting window.
What line for a fish finder rig?
12–30 lb mainline across the solved builds, with a leader on 6 of them. Braid ratings are compared to the rod by diameter, not printed test, because rod line ratings are written for mono.
What fish is a fish finder rig for?
We solve it for Channel Catfish, Blue Catfish, Common Carp, Striped Bass, Redfish and Flounder. Every one of them clears the engine.
What knot do I tie a fish finder rig with?
the Improved Clinch Knot (85% retained strength), the Uni Knot (90% retained strength) and the Snell Knot (95% retained strength). Where a leader meets braid, use a line-to-line knot such as the double uni or the FG.
When should I not fish a fish finder rig?
Rocky bottom with a heavy weight that wedges, and lure fishing. If the bait should move, this is the wrong rig.