load balancing between two ISPs

Hi, I can’t create rules for balancing between 2 ISPs
I can’t activate 2nd route when it created.
If I use “routing mark” second ISP becomes active, but lan users lose Internet connection.
Please, prompt configuration rules.
I tried like that (without routing mark)

interface set ether1 name="LAN"
interface set ether2 name="ISP1"
interface set ether3 name="ISP2"
ip address add address=192.168.1.1/24 interface=LAN
ip address add address=200.0.0.10/30 interface=ISP1
ip address add address=100.0.0.10/29 interface=ISP2
ip route add dst-address=0.0.0.0/0 gateway=200.0.0.9
ip route add dst-address=0.0.0.0/0 gateway=100.0.0.8 It isn't activated
ip dhcp-server setup
ip dns set servers=192.168.1.2,8.8.8.8
ip firewall nat add chain=srcnat action=masquerade out-interface=!LAN
ip firewall filter add chain=forward dst-address=192.168.1.0/24 action=accept
ip firewall filter add chain=forward src-address=192.168.1.0/24 action=accept

And with routing mark

ip route add gateway=100.0.0.9 routing-mark=to-isp2
ip route add gateway=200.0.0.9 routing-mark=to-isp1

Both providers are activated but no Internet.
A tried use this

ip route add gateway=100.0.0.9,200.0.0.9

But I’m not sure that both options work. All workstations tried connect using isp1.

PCC

You can see this links: http://mikrotikroutersetup.blogspot.com/p/mikrotik-router-policy-routing.html