diff --git a/.travis.yml b/.travis.yml
index 2eb1bad..2b407ca 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,7 @@
 sudo: required  
 cache: pip
+os: linux
+dist: bionic
 language: python
 python:
   - "3.6"
@@ -7,9 +9,11 @@ env:
   global:
   - COMMIT=${TRAVIS_COMMIT::8}
 install:
+  - sudo apt-get install libdb-dev
   - pip3 install cython
-  - pip install -r requirements.txt  
-  - pip install -r optional-requirements.txt
+  - pip3 install -r requirements.txt
+  - pip3 install -r optional-requirements.txt
+  - pip3 install .
 script:
   - py.test -s -vv bigsi/tests/
 after_success:
diff --git a/bigsi/bitvector.py b/bigsi/bitvector.py
deleted file mode 100644
index efc94ad..0000000
--- a/bigsi/bitvector.py
+++ /dev/null
@@ -1,29 +0,0 @@
-from bitarray import bitarray
-import numpy as np
-
-
-class BitArray(bitarray):
-    def __init__(self, *args, **kwargs):
-        super().__init__()
-
-    def setbit(self, i, bit):
-        if i < 0:
-            raise ValueError("Index must be >= 0")
-        try:
-            self[i] = bit
-            return self
-        except IndexError:
-            self.extend([False] * (1 + i - self.length()))
-            return self.setbit(i, bit)
-
-    def getbit(self, i):
-        try:
-            return self[i]
-        except IndexError:
-            return False
-
-    def indexes(self):
-        return np.where(self)[0].tolist()
-
-    def colours(self):
-        return self.indexes()
diff --git a/bigsi/bloom/bloomfilter.py b/bigsi/bloom/bloomfilter.py
index de4dfaf..ff971a2 100644
--- a/bigsi/bloom/bloomfilter.py
+++ b/bigsi/bloom/bloomfilter.py
@@ -18,6 +18,7 @@ def __init__(self, m, h):
         self.m = m
         self.h = h
         self.bitarray = bitarray(self.m)
+        self.bitarray.setall(0)
 
     def __hashes(self, element):
         return generate_hashes(element, self.h, self.m)
@@ -30,10 +31,3 @@ def update(self, elements):
         for e in list(elements):
             self.add(e)
         return self
-
-
-def load_bitarray(f):
-    bloomfilter = bitarray()
-    with open(f, "rb") as inf:
-        bloomfilter.fromfile(inf)
-    return bloomfilter
diff --git a/bigsi/graph/bigsi.py b/bigsi/graph/bigsi.py
index fb66009..83a416a 100644
--- a/bigsi/graph/bigsi.py
+++ b/bigsi/graph/bigsi.py
@@ -11,7 +11,7 @@
 from bigsi.utils import convert_query_kmers
 from bigsi.utils import seq_to_kmers
 from bigsi.utils import bitwise_and
-from bigsi.utils import non_zero_bitarrary_positions
+from bigsi.utils import non_zero_bitarray_positions
 from bigsi.storage import get_storage
 from bigsi.scoring import Scorer
 from bigsi.constants import DEFAULT_NPROC
@@ -190,7 +190,7 @@ def search(self, seq, threshold=1.0, score=False):
         ]
 
     def exact_filter(self, kmers_to_colours):
-        colours_with_all_kmers = non_zero_bitarrary_positions(
+        colours_with_all_kmers = non_zero_bitarray_positions(
             bitwise_and(kmers_to_colours.values())
         )
         samples = self.get_sample_list(colours_with_all_kmers)
diff --git a/bigsi/tests/bloom/test_bloomfilter.py b/bigsi/tests/bloom/test_bloomfilter.py
new file mode 100644
index 0000000..8c4c88e
--- /dev/null
+++ b/bigsi/tests/bloom/test_bloomfilter.py
@@ -0,0 +1,80 @@
+from bitarray import bitarray
+from random import choice
+from hypothesis import assume, given, strategies as st
+
+from bigsi.bloom import generate_hashes
+from bigsi.bloom import BloomFilter
+
+
+def test_generate_hashes():
+    assert generate_hashes("ATT", 3, 25) == {2, 15, 17}
+    assert generate_hashes("ATT", 1, 25) == {15}
+    assert generate_hashes("ATT", 2, 50) == {15, 27}
+
+
+@given(len_bloom_filter=st.integers(min_value=1, max_value=1000),
+       num_hash_functions=st.integers(min_value=1, max_value=3))
+def test_bloomfilter_created_with_initialisation(len_bloom_filter, num_hash_functions):
+    bloom_filter = BloomFilter(m=len_bloom_filter, h=num_hash_functions)
+    assert bloom_filter.bitarray == bitarray("0" * len_bloom_filter)
+
+
+@given(len_bloom_filter=st.integers(min_value=100, max_value=2000),
+       num_hash_functions=st.integers(min_value=1, max_value=3),
+       len_kmer=st.integers(min_value=3, max_value=31),
+       num_kmers=st.integers(min_value=1, max_value=10))
+def test_bloomfilter_updated_success(len_bloom_filter, num_hash_functions, len_kmer, num_kmers):
+    kmers = _generate_random_kmers(len_kmer, num_kmers)
+    hashes = _generate_kmer_hashes(kmers, len_bloom_filter, num_hash_functions)
+
+    expected = bitarray("0" * len_bloom_filter)
+    for h in hashes:
+        expected[h] = True
+
+    bloom_filter = BloomFilter(m=len_bloom_filter, h=num_hash_functions)
+    bloom_filter.update(kmers)
+
+    assert bloom_filter.bitarray == expected
+
+
+@given(len_bloom_filter=st.integers(min_value=100, max_value=2000),
+       num_hash_functions=st.integers(min_value=1, max_value=3),
+       len_kmer=st.integers(min_value=3, max_value=31),
+       num_kmers=st.integers(min_value=1, max_value=10))
+def test_bloomfilters_updated_with_same_kmers(len_bloom_filter, num_hash_functions, len_kmer, num_kmers):
+    kmers = _generate_random_kmers(len_kmer, num_kmers)
+
+    bloom_filter1 = BloomFilter(m=len_bloom_filter, h=num_hash_functions)
+    bloom_filter1.update(kmers)
+    bloom_filter2 = BloomFilter(m=len_bloom_filter, h=num_hash_functions)
+    bloom_filter2.update(kmers)
+
+    assert bloom_filter1.bitarray == bloom_filter2.bitarray
+
+
+@given(len_bloom_filter=st.integers(min_value=100, max_value=2000),
+       num_hash_functions=st.integers(min_value=1, max_value=3),
+       len_kmer=st.integers(min_value=3, max_value=31),
+       num_kmers=st.integers(min_value=1, max_value=10))
+def test_bloomfilters_updated_with_different_kmers(len_bloom_filter, num_hash_functions, len_kmer, num_kmers):
+    kmers1 = _generate_random_kmers(len_kmer, num_kmers)
+    hashes1 = _generate_kmer_hashes(kmers1, len_bloom_filter, num_hash_functions)
+    kmers2 = _generate_random_kmers(len_kmer, num_kmers)
+    hashes2 = _generate_kmer_hashes(kmers2, len_bloom_filter, num_hash_functions)
+
+    assume(hashes1 != hashes2)
+
+    bloom_filter1 = BloomFilter(m=len_bloom_filter, h=num_hash_functions)
+    bloom_filter1.update(kmers1)
+    bloom_filter2 = BloomFilter(m=len_bloom_filter, h=num_hash_functions)
+    bloom_filter2.update(kmers2)
+
+    assert bloom_filter1.bitarray != bloom_filter2.bitarray
+
+
+def _generate_random_kmers(len_kmer, num_kmers):
+    return [''.join(choice("ACGT") for _ in range(len_kmer)) for _ in range(num_kmers)]
+
+
+def _generate_kmer_hashes(kmers, len_bloom_filter, num_hash_functions):
+    return {h for kmer in kmers for h in generate_hashes(kmer, num_hash_functions, len_bloom_filter)}
diff --git a/bigsi/tests/bloom/test_create_bloomfilter.py b/bigsi/tests/bloom/test_create_bloomfilter.py
deleted file mode 100644
index 74d519c..0000000
--- a/bigsi/tests/bloom/test_create_bloomfilter.py
+++ /dev/null
@@ -1,21 +0,0 @@
-from bigsi.bloom import generate_hashes
-from bigsi.bloom import BloomFilter
-
-
-def test_generate_hashes():
-    assert generate_hashes("ATT", 3, 25) == {2, 15, 17}
-    assert generate_hashes("ATT", 1, 25) == {15}
-    assert generate_hashes("ATT", 2, 50) == {15, 27}
-
-
-def test_create_bloom():
-    for i in range(3):
-        kmers1 = ["ATT", "ATC"]
-        bloomfilter1 = BloomFilter(m=25, h=3)
-        bloomfilter1.update(kmers1)
-
-        kmers2 = ["ATT", "ATT"]
-        bloomfilter2 = BloomFilter(m=25, h=3)
-        bloomfilter2.update(kmers2)
-
-        assert bloomfilter1.bitarray != bloomfilter2.bitarray
diff --git a/bigsi/tests/cli/__init__.py b/bigsi/tests/cli/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/bigsi/tests/graph/__init__.py b/bigsi/tests/graph/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/bigsi/tests/graph/test_end_to_end.py b/bigsi/tests/graph/test_end_to_end.py
index 1d74381..c4e9efb 100644
--- a/bigsi/tests/graph/test_end_to_end.py
+++ b/bigsi/tests/graph/test_end_to_end.py
@@ -91,9 +91,6 @@ def test_exact_search():
         bigsi.delete()
 
 
-@pytest.mark.skip(
-    reason="Passes in isolation, but fails when run with the rest of the tests"
-)
 def test_inexact_search():
     for config in CONFIGS:
         get_storage(config).delete_all()
diff --git a/bigsi/tests/matrix/__init__.py b/bigsi/tests/matrix/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/bigsi/tests/storage/__init__.py b/bigsi/tests/storage/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/bigsi/tests/utils/test_fncts.py b/bigsi/tests/utils/test_fncts.py
new file mode 100644
index 0000000..5a8bd29
--- /dev/null
+++ b/bigsi/tests/utils/test_fncts.py
@@ -0,0 +1,16 @@
+from bitarray import bitarray
+from hypothesis import given, strategies as st
+
+from bigsi.utils.fncts import non_zero_bitarray_positions
+
+
+@given(byte_values=st.lists(min_size=0, max_size=2000, elements=st.integers(min_value=0, max_value=255)))
+def test_non_zero_bitarrary_positions_success(byte_values):
+    bit_array = bitarray()
+    bit_array.frombytes(bytes(byte_values))
+
+    expected = [index for index, bit in enumerate(bit_array) if bit]
+
+    result = non_zero_bitarray_positions(bit_array)
+
+    assert result == expected
diff --git a/bigsi/utils/fncts.py b/bigsi/utils/fncts.py
index 22b2b60..b21dc1b 100644
--- a/bigsi/utils/fncts.py
+++ b/bigsi/utils/fncts.py
@@ -1,9 +1,6 @@
-import hashlib
-import struct
-import sys
 import logging
-from functools import reduce
 import numpy as np
+from functools import reduce
 from itertools import islice, chain
 
 logger = logging.getLogger(__name__)
@@ -25,8 +22,8 @@ def bitwise_and(bitarrays):
     return reduce(lambda x, y: x & y, bitarrays)
 
 
-def non_zero_bitarrary_positions(bitarray):
-    return np.where(bitarray)[0].tolist()
+def non_zero_bitarray_positions(bitarray):
+    return np.where(np.unpackbits(bitarray))[0].tolist()
 
 
 def chunks(l, n):
diff --git a/optional-requirements.txt b/optional-requirements.txt
index 14bfc29..b9fca7f 100644
--- a/optional-requirements.txt
+++ b/optional-requirements.txt
@@ -1,4 +1,4 @@
 # Optional Storage
-python-rocksdb
+#python-rocksdb # temporarily commented out so that installation will not fail if not using RocksDB
 bsddb3==6.2.5
 uWSGI==2.0.18
\ No newline at end of file