(After writing this, I realize it's very long! I'm sorry! I have a pretty good idea at the bottom, though.)
Hi Sandra, I think you could make a few improvements for little price. I'll get to the worms in a second. First of all, I would recommend that you upgrade to a 5 gallon glass aquarium (it doesn't have to be glass). Around here, those are about ten dollars. (Be sure you also get a proper lid.) Many people will tell you that ten gallons is the minimum. If you only have one newt, and it is a small species like a cynops orientalis, a five gallon would be fine. I would put 2-3 gallons of water in it.
Okay, about the worms. First of all, they are most likely live blackworms, not bloodworms. Newts are opportunistic feeders. This means they will eat whatever they can, because they never know, in the wild, when the next meal will come. So basically, many newts will eat as much as you will give them. I have only a few suggestions, none of which are great.
1. Where do you go for 4-5 days? If it's from college to home, you should keep the newt where you are for 4-5 days and not where you are for 2-3 days. My college only allowed us to have "fish" but I was able to get by with the newts by telling my RA that they never came out of the water (even though the newt was on the floating island half of the time, she didn't care really).
2. Although it's alot to ask, maybe someone could use a turkey baster and put some worms in the feeding dish for you on the middle of your "away-ness." Like if you're gone for five days, they could do it on the second or third day.
3. Honestly, a very healthy newt would be fine being fed once a week, but this is really risky. What if the newt becomes ill and needs care every day that you cannot provide?
4. I have one last idea, but it's a pretty good one. Go ahead and expand to that ten gallon tank to provide a bigger area with more water volume. For a firebelly, put in about 4 gallons of water. Use NO substrate, but rather have a bare glass bottom. If you put in a few small (about half-inch across) stones (by a few I mean like 8 or something) spread out around the bottom, you can put the blackworms in there and the newt will have to hunt for them while you are gone. This poses one problem though. Blackworms are good at hiding, and it's easy to not realize how many are in there, polluting your water. So, you would have to overturn the little stones and suck out old worms when you came back in town.
Another option for live food is a few ghost shrimp. Let me just say this though, I've never seen my cynops eat the shrimp, only my tarichas who are quite a bit larger. However, I always pick out the large ghost shrimp so that they've live a while and provide my taricha with entertainment and a challenge in trying to catch them! Lol. However, it wouldn't hurt to buy a few small ones to put in with your cynops, they would at least clean up the tank a bit and they're fun to watch. Mine really love to climb and hide in a plastic plant I bought that suctions to the side of the tank and looks like vines, the newt likes it too.
I hope some of these ideas help you out.
