Acrochordus granulatus is very thermal-sensitive, and sudden temperature changes will shock the animal, to possible death!  I know this first hand from when I brought Flaps home is his dirty (feces?) water and felt the need to change it up, especially since it was probably too cool.  Well, though it felt luke-warm to me, it made Flaps writhe in anguish with mouth agape - my heart jumped in my throat that I had almost lost him on the first day home (!) which spelled too warm to me.  Luckily, I was still holding him and my girlfriend standing by for help, so I immediately pulled him out, and We refilled with slightly cooler water.  Anyway, the nicely-provided Water Temperature Charts on Acrochordus.com are indicative of the naturally higher temperatures occurring in the range of these snakes than was originally led to believe.

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So, then, to answer many people’s predominant concern about the "notoriously difficult" husbandry of the genus Acrochordus, I would say they're not so much difficult as just misunderstood, especially in regards to A. granulatus.  It is the hope of the select few who have succeeded with Acrochordus spp. (namely, A. granulatus) to one day figure out what is ultimately necessary husbandry-wise to ensure long-term success and happiness for the animal(s) in captivity, so that--and I do paraphrase from here on out--one day, perhaps the common 15-year-old herper will be able to keep one like a corn snake! :)

Now, in conclusion of everything, I will provide my first-ever care sheet (for Acrochordus granulatus of course) in itemization style:

Tank: 20G-Long or 29G at the biggest should be sufficient since the water level needs to be kept shallow, and You want to be able to reach down easy enough.

Water: FRESH!!  ...and 4" if possible though can be difficult to set up a tank so low, thus I believe 5"-5.5" is acceptable, especially if there is a lot of furniture for the snake(s) to cling to and grasp when hunting, and to ‘trap’ the fish within so to speak.

Temperature: 86-88 degrees Fahrenheit.  NOTE: the use of two heaters--one on each end, or like mine: one front-right, other back-left--is recommended in case one fails, but also so that the temperature is consistent throughout the aquarium...no temperature gradient here!

pH: <7 (= acidic) is all that should be paid attention to.  Of course, 5.5-6.5 would be optimum, but pH is not as crucial to these snakes as once thought.

gH (General Hardness reading magnesium and calcium) and kH (Carbonate Hardness): 2-3, or as low as possible.  Id est, You want soft water, and using R.O. (Reverse Osmosis) water or bottled distilled water (such as from Target where I once purchased it until I started using my Father's R.O. machine) are the preferred methods of obtaining soft water which should also have a natural pH of 6.0, do note.  Should You live an area with generally "pristine" water such as in Western MA :) You could rely on that, but it's iffy...

Filtration: a small (fully submersible) biological filter (exempli gratia, the Zoo Med Turtle Clean 318) with perhaps a small pump in opposite-diagonal corner, or even an xP1 canister filter by Rena.  Don't make a river, as these snakes are typically in "stagnant" waters, but to keep a lid on the NH3 and NO2 (nitrites), You need fair circulation.  I had actually failed in this department because of all the décor I have in my tank, but the NH3 spikes didn’t seem to affect Flaps**.

NOTE: In the wild, animals get to choose their environment (speaking of the stagnant-to-river ordeal here); in captivity, they are stuck with what We give them, so finding a good middle ground is necessary.  I advise the minimal flow that can still keep the NH3 down, still with regular water changes (see below) of course which will obviously decrease the NH3.

Substrate: small-to-medium-sized "river stones" are my preference.  Petco's 25 lb. bag fills a 29G aquarium (30" x 12") perfectly!! :)

Hideouts: I have three (3!), or 5+ if You count everything, ha!  I have one each on the left and right sides, and one in the center.  The left hideout is a Zoo Med Repti Shelter (small?); the center-left hideout is a Zilla Bark Bends (medium); and the right hideout is a Petco Reptile Cave (Large, SKU: 716111 – not on site, sorry).  I also happen to have this most perfect piece of driftwood (NOT purchased for Flaps or even my first pair of Acrochordus granulatus; was just on hand) that bows from back corner to back corner, nearly reaching the front.  It initially hindered a lot of circulation, but Flaps LOVES it!! :)  I have to scrub-clean the fungus build-up every few months, but it's no biggie.

Photoperiod: 12 hours, dropping to NO less than 11 hours in winter.  NOTE: Between the longest and shortest days of even the furthest (northern and southern) extents of Indonesia, it is only ~48 minutes difference.  In Manado, Sulawesi, Indonesia, it is only ~10 minutes difference, every day technically over 12 hours of daylight (from sunrise to sunset, see here: Sunrise and sunset in Manado).

Water Changes: This will be a pain the ass, but until if-and-when You complete the Bacteria Cycle and have things under control with sufficient flow, perform near-100% W.Cs. every day!  And do NOT scoop out/in water as You want everything gradual and calm; rather, siphon!  An aid in expediting the B.C. is Seachem Stability (S.S.) - read up on it if You'd like.  You cannot possibly overdose it, only "waste" it.  I applied 100 ml after every water change, evenly distributing it.  When things are under control, You should only have to perform weekly ~60-70% W.Cs., and You can wean off of the S.S.

Miscellaneous: I happen to have a random Petco Bamboo Stalks (SKU: 1192671 = smaller size) which Flaps likes crawling through.  The more stuff to make Your snake(s) feel at home (especially dark refuge!) without practically stopping the flow, the better, I say.  Also, pick up some Kent Marine Black Water Expert - no one carries it in my area and has to be ordered from my local fish store (L.F.S.).  It aids in natural tannins and humic acid naturally found in their waters, of course helping to make the water a little more acidic.  For my ~5 gallons, I apply 2 tsp. of it after every water change, evenly distributing it.  Lastly, applying some drops of Kent Marine Zoe after every water change isn't a bad idea, especially if Your snake(s) happen to be on goldfish which highly lack in Thiamin (B vitamins).

NOTE: Flaps had only consumed one (1) goldfish out of the couple dozen (!!) I had gotten him, and that was a few months after I stopped buying goldfish…’Goldy,’ I called him, lasted forever, and I honestly think Flaps ate him by mistake, heh…id est, I think Goldy got caught in the mix of mollies which, by the way, are more natural to this species’ diet.  I am currently trying Platies now, too, which are very similar.  I will be trying other items with Time.

As a last ‘Miscellaneous note’, I advise picking up a Seachem Ammonia Alert or two which tests for NH3 (toxic ammonia) ONLY, and which is the critical and more concerning form of ammonia, since 99% of ammonia test kits test for both NH3 and NH4 (ammonium, or iodized ammonia). 

Well, I think that is it for now.  I hope it helps!!  A detail-by-detail explanation of my whole regimen and experiences can be extracted from my log and typed for anyone who cares.  I feel the first key to having success with Acrochordus granulatus is obtaining A-grade specimens to begin with, and  Dr. Lillywhite seems to believe a large part of his success was due to receiving his specimens directly from the (Indonesian) exporter(s).  When You receive something third- or fourth-hand, by that time, the animals have stressed quite a bit, and if temperatures dropped at all--and for a substantial amount of time--"white spot fungus" (W.S.F.) usually shows its ugly face and takes its toll.  NOTE, though: The key to ridding Your animal(s) of W.S.F. seems to be keeping things simple and NOT using any (special) medications or anything; just provide clean/fresh/pure water via performing daily near-100% W.Cs.  I, personally, have not had to deal with W.S.F. on Flaps, and I am ever so thankful.