I'm pretty much in the same boat as you Galantspeedz -- we don't have any of the brand name septic treatments like Septobac etc. many are referencing from
RD.
's original Sticky thread, and if I found any local substitutes I'd be scared to death they contained something bad as he warns.
As such I've just chosen the route of going with local aquarium specific treatments:
a) while they might not be exactly the same, they're likely close enough, esp. if from popular/long-time brands people have been using for years.
b) these aqua specific products are way, way cheaper here than similar products in the West as you know (which imho in part shows how much the aqua companies are over-marking up their products, a point RD alludes to in his Sticky).
So I was using a product called Thunder Bac for about 3 months now -- you can read more about it
https://www.monsterfishkeepers.com/...e-of-probiotics-in-aquaculture.536531/page-24 (post #464) and will update that post soon about my results thus far. It's in powder form and only costs about US$3 for 50g which seems to go far (you'd only need ~5 small sp. for a 180 gallon).
But for now I'll say that because it contains one bacteria I'm not comfortable to use on a regular basis, I'm now switching to another product:
RQ Bio Plus, which is made by M.S. Royal, one of Thailand's biggest domestic aquatic product companies that's been around for quite a while. Their main product lines are water dechlorinators, conditioners and other treatments such as this one. A 500ml bottle costs 150 Thb (~US$5).
Dosage is 1cc for every 50 liters, so 500ml should treat about 25,000 liters if my math is correct. I'm not really worried about shelf life as it's made locally and they seem to sell a good amount of it so I doubt bottles really sit on the shelves very long and are replaced with new stock pretty quick -- they're in just about every LFS in the country.
From its description it seems that RQ Bio Plus contains both probiotic bacteria for breaking down organic waste, and also some denitrifying bacteria as well, so seems kinda similar to Seachem Stability.
"-- RQ Bio Plus is a product consisting of many strains of microbes and bacteria, which are responsible for the decomposition of waste, food scraps and waste from fish excretion. It helps to adjust the water quality to not spoil. And prevents the formation of nitro-ammonia gas, that causes various diseases in fish. It is useful for raising fish in an aquarium or fish pond.
-- Should refill every 1 month or every time you change a new water. Can use with both fresh and salt water."
Of course I have to trust they're putting in all good stuff and nothing bad (as mentioned in one of RD's links in Sticky), but given they've been around a long time and are very popular I'm giving them the benefit of the doubt unless I ever see adverse effects.
I'd be curious to find out what is the total price of genuine Canadian Septobac to Singapore with shipping and possible customs duties, so plz update. If not crazy I wouldn't blame you for going with something tried and tested that other members have used, but personally for me I'm pretty sure it wouldn't be cost effective compared to local aquarium specific products, even if they are (possibly) a bit inferior.
So maybe next time you're at Chatuchak you can pick up these or other similar products to try; I'll update my own experiences either here or on RD's Sticky discussion thread.