Depthfinders at Night

[AWH]

What is it that causes your depthfinders to go nuts when the sun goes down? When I'm out after dark, almost as soon as the sun goes down, the graph begins to black out from the bottom up with clutter. No chance at watching your graph for fish anymore. I've played with the sensitivity and everything else that I can think of and nothing helps. At times, I can't even rely on it for depth. I was trolling after dark a few weeks ago and I had no idea how deep I was. It would jump around from 50 to 10 to 40 to 6 to 30 to....I'm pretty sure I was in 35 to 40 feet the whole time. But it would be nice to be able to count on the graph readings when it's dark out. Why does this happen and what can be done to cure this problem?

Thanks,

Aaron

[Surface Tension]

Most likely plankton coming off the bottom. This doesn't happen on all lakes. All you can do is turn your gain down to where you can still pick up bottom.

[AWH]

I fish a lot of different lakes. I can't think of one that it doesn't happen to me on. Sometimes it's worse than others. But I can't remember anywhere that it hasn't happened. That's what I've always figured, that it must be plankton. But that's a heck of a lot of plankton for the sonar to not even be able to detect the bottom. Usually, it's just the screen going black and I can still tell depth. But that was nuts when I had no clue how deep I was. And it wasn't for just a short period of time!

Aaron

[Surface Tension]

What model sounder do you have? You might try turning up the noise reduction and see if that helps.

[AWH]

I have a Lowrance X-85. How do you turn up the noise reduction?

[Chev_trucks501]

Hey AWH,

If my memory serves me right, you work at Gander in Baxter right?

[AWH]

Your memory serves you correctly.

[Surface Tension]

You have ASP Advanced Signal Processing. If you turn that on it'll set noise reduction along with sensitivity automaticly. You may also have a manual setting for noise reduction in a sub menu under Sonar but I'm not positive with he X87.