Tools

CO2 calculator

Estimate dissolved CO2 from KH and pH values. Use the chart to visualize target ranges and confirm your reading.

KH + pH to CO2 ppm

Freshwater focus

Calculate dissolved CO2

Use the standard KH/pH relationship for planted freshwater aquariums.

Saltwater systems need a different CO2 approach. Use marine-specific guidelines for reef tanks.

CO2 reference chart

Cross-reference KH and pH values to compare your result with typical CO2 ranges for planted tanks.

KH
6.0
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
7.0
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
8.0
1
30
24
19
15
12
9
8
6
5
4
3
2
2
2
1
1
1
1
0
0
0
2
60
48
38
30
24
19
15
12
10
8
6
5
4
3
2
2
2
1
1
1
1
3
90
71
57
45
36
28
23
18
14
11
9
7
6
5
4
3
2
2
1
1
1
4
120
95
76
60
48
38
30
24
19
15
12
10
8
6
5
4
3
2
2
2
1
5
150
119
95
75
60
47
38
30
24
19
15
12
9
8
6
5
4
3
2
2
2
6
180
143
114
90
72
57
45
36
29
23
18
14
11
9
7
6
5
4
3
2
2
7
210
167
133
105
84
66
53
42
33
26
21
17
13
11
8
7
5
4
3
3
2
8
240
191
151
120
96
76
60
48
38
30
24
19
15
12
10
8
6
5
4
3
2
9
270
214
170
135
107
85
68
54
43
34
27
21
17
14
11
9
7
5
4
3
3
10
300
238
189
150
119
95
75
60
48
38
30
24
19
15
12
9
8
6
5
4
3
11
330
262
208
165
131
104
83
66
52
42
33
26
21
17
13
10
8
7
5
4
3
12
360
286
227
180
143
114
90
72
57
45
36
29
23
18
14
11
9
7
6
5
4
13
390
310
246
195
155
123
98
78
62
49
39
31
25
20
16
12
10
8
6
5
4
14
420
334
265
210
167
133
105
84
67
53
42
33
27
21
17
13
11
8
7
5
4
15
450
357
284
226
179
142
113
90
71
57
45
36
28
23
18
14
11
9
7
6
5
16
480
381
303
241
191
152
121
96
76
60
48
38
30
24
19
15
12
10
8
6
5
17
510
405
322
256
203
161
128
102
81
64
51
41
32
26
20
16
13
10
8
6
5
18
540
429
341
271
215
171
136
108
86
68
54
43
34
27
21
17
14
11
9
7
5
19
570
453
360
286
227
180
143
114
90
72
57
45
36
29
23
18
14
11
9
7
6
20
600
477
379
301
239
190
151
120
95
76
60
48
38
30
24
19
15
12
10
8
6
KH (rows)pH (columns)

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