Screen Space Reflections Artifacts - opengl

Question

When I implemented SSR I encountered the problem of artifacts. Below I present the code and screenshots.
Fragment SSR shader:
#version 330 core
uniform sampler2D normalMap; // in view space
uniform sampler2D colorMap;
uniform sampler2D reflectionStrengthMap;
uniform sampler2D positionMap; // in view space
uniform mat4 projection;
uniform vec3 skyColor = vec3(0.1, 0, 0.5);
in vec2 texCoord;
layout (location = 0) out vec4 fragColor;
const int binarySearchCount = 10;
const int rayMarchCount = 30;
const float step = 0.05;
const float LLimiter = 0.2;
const float minRayStep = 0.2;
vec3 getPosition(in vec2 texCoord) {
return texture(positionMap, texCoord).xyz;
}
vec2 binarySearch(inout vec3 dir, inout vec3 hitCoord, inout float dDepth) {
float depth;
vec4 projectedCoord;
for(int i = 0; i < binarySearchCount; i++) {
projectedCoord = projection * vec4(hitCoord, 1.0);
projectedCoord.xy /= projectedCoord.w;
projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
depth = getPosition(projectedCoord.xy).z;
dDepth = hitCoord.z - depth;
dir *= 0.5;
if(dDepth > 0.0)
hitCoord += dir;
else
hitCoord -= dir;
}
projectedCoord = projection * vec4(hitCoord, 1.0);
projectedCoord.xy /= projectedCoord.w;
projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
return vec2(projectedCoord.xy);
}
vec2 rayCast(vec3 dir, inout vec3 hitCoord, out float dDepth) {
dir *= step;
for (int i = 0; i < rayMarchCount; i++) {
hitCoord += dir;
vec4 projectedCoord = projection * vec4(hitCoord, 1.0);
projectedCoord.xy /= projectedCoord.w;
projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
float depth = getPosition(projectedCoord.xy).z;
dDepth = hitCoord.z - depth;
if((dir.z - dDepth) < 1.2 && dDepth <= 0.0) return binarySearch(dir, hitCoord, dDepth);
}
return vec2(-1.0);
}
void main() {
float reflectionStrength = texture(reflectionStrengthMap, texCoord).r;
if (reflectionStrength == 0) {
fragColor = texture(colorMap, texCoord);
return;
}
vec3 normal = texture(normalMap, texCoord).xyz;
vec3 viewPos = getPosition(texCoord);
// Reflection vector
vec3 reflected = normalize(reflect(normalize(viewPos), normalize(normal)));
// Ray cast
vec3 hitPos = viewPos;
float dDepth;
vec2 coords = rayCast(reflected * max(-viewPos.z, minRayStep), hitPos, dDepth);
float L = length(getPosition(coords) - viewPos);
L = clamp(L * LLimiter, 0, 1);
float error = 1 - L;
vec3 color = texture(colorMap, coords.xy).rgb * error;
if (coords.xy != vec2(-1.0)) {
fragColor = mix(texture(colorMap, texCoord), vec4(color, 1.0), reflectionStrength);
return;
}
fragColor = mix(texture(colorMap, texCoord), vec4(skyColor, 1.0), reflectionStrength);
}
Result without blackout (without * error):
Result with blackout:
Note: blue is filled specifically to see artifacts
And one more question, what is the best way to add fresnel without harming scene?