how to correct   reduction of diff  ?
**the diff is established manually using a wallet+diff   oceanpool
3 workers  wallet+24000** 
[2018-05-04 11:15:52] verbose: 1
[2018-05-04 11:16:12] #013 accepted (29412/0+6) diff 24000 ip 172.25.27.34 (124 ms)
[2018-05-04 11:16:12] #015 accepted (29413/0+6) diff 24000 ip 172.25.27.34 (157 ms)
[2018-05-04 11:16:15] #013 accepted (29414/0+6) diff 24000 ip 172.25.27.34 (407 ms)
[2018-05-04 11:16:24] 2.00 kH/s, shares: 29414/0 +5, upstreams: 3, miners: 3 (max 6) +0/-0
[2018-05-04 11:16:28] #013 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:28] #015 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:30] #017 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:33] #015 accepted (29415/0+6) diff 24000 ip 172.25.27.34 (1006 ms)
[2018-05-04 11:16:47] #017 accepted (29416/0+6) diff 24000 ip 172.25.27.34 (4759 ms)
[2018-05-04 11:16:52] #013 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:52] #015 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:54] #013 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:54] #015 new job from de.moneroocean.stream:10016 diff 24000
[2018-05-04 11:16:54] verbose: 0

**at connection more than three miners I observe reduction of diff
6 workers    wallet+13000**

[2018-05-04 11:12:57] verbose: 1
[2018-05-04 11:12:57] #065 accepted (87990/0+7) diff 2423 ip 172.25.27.114 (288 ms)
[2018-05-04 11:12:59] #068 accepted (87991/0+7) diff 1846 ip 172.25.27.102 (219 ms)
[2018-05-04 11:13:00] #066 accepted (87992/0+7) diff 13000 ip 172.25.27.102 (160 ms)
[2018-05-04 11:13:01] #065 accepted (87993/0+7) diff 2423 ip 172.25.27.114 (391 ms)
[2018-05-04 11:13:01] #070 accepted (87994/0+7) diff 4191 ip 127.0.0.1 (140 ms)
[2018-05-04 11:13:03] #066 new job from de.moneroocean.stream:10008 diff 13000
[2018-05-04 11:13:03] #069 new job from de.moneroocean.stream:10008 diff 13000
[2018-05-04 11:13:03] #070 new job from de.moneroocean.stream:10008 diff 4191
[2018-05-04 11:13:04] #068 new job from de.moneroocean.stream:10008 diff 1846
[2018-05-04 11:13:05] #069 accepted (87995/0+7) diff 13000 ip 172.25.27.102 (774 ms)
[2018-05-04 11:13:05] #065 new job from de.moneroocean.stream:10008 diff 2423
[2018-05-04 11:13:05] #067 new job from de.moneroocean.stream:10008 diff 2423
[2018-05-04 11:13:08] #068 accepted (87996/0+7) diff 1846 ip 172.25.27.102 (254 ms)
[2018-05-04 11:13:09] #070 accepted (87997/0+7) diff 4191 ip 127.0.0.1 (148 ms)
[2018-05-04 11:13:10] #070 accepted (87998/0+7) diff 4191 ip 127.0.0.1 (118 ms)
[2018-05-04 11:13:11] #068 accepted (87999/0+7) diff 1846 ip 172.25.27.102 (111 ms)
[2018-05-04 11:13:16] #070 new job from de.moneroocean.stream:10008 diff 4182
[2018-05-04 11:13:18] verbose: 0


how to correct   reduction of complexity  ?