General
Homalopsis buccata snakes are generally very hardy snakes that are not difficult to keep. However, their needs are somewhat specialized compared to the husbandry of most types of water snakes. Like the Chinese watersnakes, these are very aquatic. Unlike most types of water snakes - These guys really love the water. They live in conditions that are water and 100% humidity. They don't develop the dreaded "water blisters" that most other water snakes do.
These snakes stay in the water until the water temps start reaching 89-90F (31.6-32.2C) Their feeding is down right voracious.
Below is a basic explanation of the way they have been housed  my care.

Current setup
9-05-07

Plants and Top-Coverage
I always recommend Live plants for aquatic setups. However, these snake are currently setup Fish-only style. They are provided with top-coverage via the cork bark, which also doubles as a land area.

Cage
These snakes are housed in three large tubs (39"x18"x7") which are run through a single filtration system. The top has been modified to allow for ventilation, a hot spot and a cool spot. One tub has been modified for the canister filter plumbing.

Filtration
This setup is ~65gal total water and is currently filtered with a Rena Filstar xP2 canister filter and a 30gal sump. The sump contains a 29gal undergravel filter with a 2 penguin 1140 (300gph) forward-flow powerhead setup, a Quiet One 3000 return pump with dual Hydor #5 pre-filter sponges and a 3rd penguin 1140 powerhead that operates a 4  Hydor #5 sponge filter inside.

Water Quality
I currently use 100% hard tap water (Gh18, Kh14, pH 7.5-7.7, TDS ~300ppm) and do 1-2x 40% water changes per week. TDSs range from about 280ppm after a water change to ~360ppm before. The snakes seem very happy with this setup.  I add Kent Marine's Zoe for vitamin supplement and Black Water Expert and Botanica Humic for tannins and humic acids at every water change. See Old Setup for previous setup.

Temperature
The water temperature varies in this setup from a low of 82F (27.7C) to a high of ~89F(31.6C). When the water starts reaching 89-90F (31.6-32.2C) the snakes start getting out of the water. They really seem to enjoy water temps in the 82-86F (27.7-30C) range.

Under the hot spot are 1 or more pieces of cork bark for them to hide under or bask on top of. Generally these snakes do not seem to use the hot spot very much at all. Apparently they like lower temps in the 80'sF.

Photoperiod
In their natural environment the photoperiod is 12 hrs of daylight and 12 hrs of darkness. I am currently giving these Puff - Faced Watersnakes 12hrs of light,/12 hrs of Darkness.
Unlike Acrochordus snakes, Homalopsinae snakes don't seem to mind bright light at all. Currently they only recieve ambient light and a 60w hot spot dimmed to ~35w. They seem very content.

Water Level
These snakes are very aquatic. They love the water. Currently, they are housed in water ~3- 4" deep.

Substrate
I just use standard white aquarium gravel over an undergravel filter in the sump. In the main containers I currently do not have any substrate. I plan to add a thin (~1") layer of (probably) Flourite for appearance, contact security and mulm management.

Feeding
These snakes are voracious feeders. I feed them both individually and by just placing fish in the water. I feed the fish both dead (including F/T)  and alive. The snakes don't seem to care--they just love to eat. I have fed them minnows, shiners and lg comets. I have recently gone to feeding F/T raw catfish fillets and nuggets. The long-term Homalopsis buccata took to the fillets pretty quickly. Some scenting with F/T minnows was necessary, but it didn't take much to get them switched over. The newer Homalopsis buccata are mixed in their response to the F/T catfish fillets even with minnow scenting. I don't expect any problems getting them switched over though. I do and will continue to offer whole fish for more complete nutritional value.

Handling
Puff - Faced water snakes are a lot like most "Watersnakes". They can tolerate handling.  I rarely handle these Homalopsis buccata, because I really do not see the need. Everything that I need to do can be done with them in the setup and a little care. I have handled them and overall they accept handling very well. However, these snakes, like the Chinese watersnakes, do seem a bit "Soft-bodied". Its not hard to tell that they live a very buoyant lifestyle.

Aggressiveness
These snakes (all 9 of them) have not been aggressive at all. I really am truly amazed. Figuring that they are A) water snakes and B) Asian water snakes--I assumed they would show some aggression--at least initially. Nope. Not one bit of aggression from any of them.

Reproduction
I do not understand clearly at this point how the reproductive cycle of these snakes works. However, they are a nuisance in their native lands. According to field studies--they don't have a reproductive season. They produce off-spring year-round with an Oct-Mar peak period, and Nov-Dec being the top of the peak. I will update this section as I get further down the road in this area. I just need to do some more research. However, from what I have learned--I don't think they will be very difficult to breed in captivity.

 Disclaimer

This Caresheet is offered on the Puff - Faced water snake - Homalopsis buccata as is. This Caresheet is not offered in reference to any snake other than the Puff - Faced water snake - Homalopsis buccata and even so--use at You Own Risk!

This general information should be transferable to one or more other Homalopsinae species, but I offer no guarantees of any kind.

Additionally, this caresheet is obviously based upon admittedly limited experience! It is not intend to be a recipe of do this, do this, do this---Bam! You have a cake. It's intent is to offer more of a conceptual understanding of these fascinating creatures and their apparent needs both in the wild and in captivity.