You must check your system periodically to ensure that it is water-tight. You can do that by performing visual checks. Make sure to check each of the tubes for damages after you have put everything together. Once that is done, try testing the entire loop. For this, you will have to run the whole loop using just the pump-on facility for a day at least. Make sure to do this using distilled water. If there are any leaks then this will let you know.  Ensure that the fittings are very tight on each of the connections. This will keep the liquid from spilling out. Once that's all done, double-check it all so that everything is fine.