Simplest way to create a connection and execute a query on replicaset with mongoose?

I'm trying to execute a specific query on replica set... but without success.

What is the simplest way to create a connection and execute a query on replicaset with mongoose?

My code-1:

var mongoose = require('mongoose');
mongoose.connect('mongodb://user:pass@host:port/db,user:pass@host2:port/db');

var someSchema = new mongoose.Schema({...}, { read: 'secondary' });
var some = mongoose.model('Some', someSchema);

some.find(...) -> err [Error: not authorized for query on bd.collection]

My code-2:

mongoose.connect('mongodb://user:pass@host:port/db,user:pass@host2:port/db?slaveOk=true');
some.find(...) -> err [Error: not authorized for query on bd.collection]

My code-3:

mongoose.connect('mongodb://user:pass@host:port/db,mongodb://user:pass@host2:port/db?slaveOk=true');
some.find(...) -> err [Error: not authorized for query on bd.collection]

My code-4:

mongoose.connect('mongodb://user:pass@end:port/db,mongodb://user:pass@end2:port/db);
some.find(...) -> err [Error: not authorized for query on bd.collection]

My code-5:

mongoose.connect('mongodb://user:pass@end:port/db,mongodb://user:pass@end2:port/db?slaveOk=true);

var someSchema = new mongoose.Schema({...});
var some = mongoose.model('Some', someSchema);

some.find(...).slaveOk() -> query executed on master (apparently)
some.find(...).read('secondary') -> query executed on master (apparently - no change on mongostat of replicaset. I'm mongoHQ user and I don't trust in mongostat from dashboard.)

SO, if I connect with mongo hostReplica:port/db -u user -p pass, and exec db.getMongo().setSlaveOk(), I can exec db.collection.find without problem.

What I'm doing wrong?

Thanks