thanks, I ran out of space in the original post.
here is the output to the serial:
Oversampling setting: 4096
C0 = 0
C1 = 47098
C2 = 41365
C3 = 30128
C4 = 28248
C5 = 32112
C6 = 29075
C7 = 15
p_crc: 15
n_crc: 15
MS5803 CRC check OK.
CLEARDATA
Analog value,Voltage(mV),Temperature,EC, Pressure(mBar), Pressuretemp
3, 14, 22.37, No solution!, 979.80, 25.75
6, 29, 22.37, No solution!, 979.80, 25.35
10, 48, 22.44, 0.28, 980.00, 25.00
13, 63, 22.44, 0.39, 980.10, 24.76
16, 78, 22.50, 0.50, 980.20, 24.52
20, 97, 22.50, 0.63, 980.00, 24.33
23, 112, 22.56, 0.74, 980.00, 24.19
26, 126, 22.56, 0.84, 980.00, 24.09
30, 146, 22.56, 0.98, 979.90, 23.99
33, 161, 22.62, 1.09, 979.80, 23.91
37, 180, 22.62, 1.22, 979.70, 23.84
40, 195, 22.69, 1.33, 980.00, 23.80
44, 214, 22.69, 1.46, 979.90, 23.76
47, 229, 22.69, 1.57, 980.00, 23.73
50, 244, 22.75, 1.68, 980.10, 23.71
54, 263, 22.75, 1.81, 980.00, 23.69
57, 278, 22.75, 1.92, 979.90, 23.68
60, 292, 22.81, 2.02, 979.90, 23.70
64, 312, 22.81, 2.16, 980.20, 23.72
67, 327, 22.81, 2.27, 979.90, 23.72
67, 327, 22.87, 2.26, 980.00, 23.72
nothing currently posts to thingspeak, the number of entries does not increase. so it is not sending an empty entry, as has happened in the past.
The reason that i've used the string class is due to when getting just the temperature and pressure sensor to upload data, thingspeak was increasing the number of entires but no adding data, sending it as a string solved that. Based on that, I thought that if I can send data as a string it should still add it.
My major issue appears to be that for whatever reason data is not being sent through to thingspeak, rather than the string form. that said, for all but the conductivity reading an int would likely be better, though I'm not sure exactly which data forms thingspeak will accept.
Thanks for your help