Forgive me but has the betta died allready? I thought it was hanging by a thread. A 25 watt heater will keep the water a consistant temperature. If you go with a heater, do not get the type that is "factory preset" usually a kinda small box looking thing that claims it is good for bowls and aquariums up to 5 gallons. They have been known to fry fish, while some have had success with them, I wouldn't trust it. When it comes time that your bio-bag (I think thats what Whisper calls them)is tatered and shreded, just replace the bag, dont discard the old one, but cut it into pieces small enough to fit in with the carbon, don't replace the carbon for that change but maybe remove some to make room for the cut bio-bag.This will allow the bacteria that has grown on the old one to "seed" the new.-However, what I'm still unsure of is what the "biological" part of the filter is... ---- The biological part of the filter is where the beneficial bacteria grows. Because the bacteria is alive it is called biological.One of the bacterias feeds off the ammonia in the water collumn (from fish crap and decayed food, etc), it. This produces nitrITE,another bacteria that is growing on the filter uses the nitrITE and turns it into nitrATE. This is good, because ammonia and nitITE are toxic to fish, nitrATE isn't toxic as long as its kept at a low level. That is why we do PWCs, to remove the nitrATE that is produced, allong with other dissolved organics in your little ecosystem. Since your aquariumis small needs to be done more frequently, as a rule of thumb. After a while you can determine what amount of water and how often it needs to be changed. One aid in this determination is a complete water test set. In the case of your filter the best place to let it grow is the white bag with the clip. The carbon also hosts the bacteria, but since the carbon exhausts after a while (or gets less effective at its job) it needs to be replaced. Rather then removeing both hosts to the bacteria and leaving no biological filtration, you just discard the old carbon and replace and keep the bag that has bacteria on it allready. As far as aging water, if you are only doing small water changes, frequently the small amount of water you are replacing should not affect the water too drastically. This is not allways the case though some well water(and city) has a high concentration of CO2 in it. This causes the water to be very acidic. When the CO2 escapes'the pH can rise rapidly to a base. This can stress fish, especially delicate ones. I have this situation and I just use an airstone in a bucket of water to "gas it out" if I amdoing a large water change. Aging over night or for a few days will also do the trick. You do however need a good water conditioner, like Prime or Amquel, that removes chlorine/chloramine and ammonia, if you have treated water from a water co----Alagae, with all the nutrients that may have built in the water + ones that are allready there + light 24/7 will give you an algae bloom, no doubt. If you do the PWC's and limit the light the algae will starve and go away. For a quicker results, use no light, or very little for a week or 2. This includes sunlight from a window. Some people have even covered the glass with a paper bag or something for a complete blackout.Read the original link I gave you, its long but no more longwinded then me. Oh yeah, the food varied diet is good, some have had great success with just a quality betta pellet like hikari. If you want to try something else you can even get live brine shrimp from a good LFS or start a hatchery of your own one day, its pretty interesting. My betta is a typical betta, a pig, he'll eat anything.

The cardboard didn't help with maintaining a moist root area, but isn't totally responsible gor what happened, either. It's very tempting to put down something like cardboard, newspapers or landscape fabric to suppress weeds, but they really do more harm then good. Weeds grow through them and root into them and become harder to deal with in the long run. It would be best to remove the cardboard, bite the proverbial bullet and pull the weeds by hand. Once the area is reasonably weed free, it's not that big a chore to keep it that way. Declined really is a better description than died. The branches showing the most extreme drooping will not revive, but the stems themselves should be fine. Cut them back to an area showing green cambium and they should put forth new growth. There is still ample time for lots of regrowth before fall. There are some root diseases which can cause this kind of rapid collapse, but I am reasonably confident that you will find very dry root balls. Should they prove to be nicely moist, you are then dealing with a more serious condition for which there is really no cure. Fingers crossed.

Turning does seem to help the process. Mine take 2 years here in MO. I don't water them but after the first year I combine several bins into one (since they shrink anyway). That turning helps the undigested stuff on the outside get mixed in, and redistributes dry and wet parts.

Are you growing this plant outside? I have one which I've had for two years. I grow it outside on the lanai in partial shade although it gets much more sun than recommended. It flowers and has gotten so big I repotted it a few months ago in a larger pot. I do not have photos to show. I'm using an old laptop and can't get it to upload photos I have on my phone. I let it go dry before watering. I do not water on any schedule. Your plant appears too wet and under-lit. I would try putting it outside in a shady area so it can adjust to higher light and slowly move it into more light after it adjusts. Make sure it is in a good draining mix. I used potting soil with a lot of perlite and small wood chips mixed in ...I grow orchids and have lots of wood chips. Make sure the soil drains well. Jane