You are quite right in ascertaining whether you are fit for a Class 1. Anyway, any reputable flying school should not be enrolling you and taking your money unless you've had a Class 1 before commencing the course.
I'm in no way related to the medical profession and by no means trying to demoralise you, but this is an extract of the "Acceptable Means of Compliance and Guidance Material to Part-MED" of the European Aviation Safety Agency. I would think that it might be the same in your country which I assume is Australia (since you mention CASA).
AMC1 MED.B.030 Haematology
(a) Abnormal haemoglobin
Applicants with abnormal haemoglobin should be investigated.
(b) Anaemia
(1) Applicants with anaemia demonstrated by a reduced haemoglobin level or haematocrit less than 32 % should be assessed as unfit and require investigation. A fit assessment may be considered in cases where the primary cause has been treated (e.g. iron or B12 deficiency) and the haemoglobin or haematocrit has stabilised at a satisfactory level.
(2) Anaemia which is unamenable to treatment is disqualifying.
I would suggest that you contact a aero-medical examiner recognised by CASA who will be able to advise you on this.