Hello and welcome
. It’s great that you want to give Thaddeus a really good home
. Love the name.
So - she will need a good two weeks “settling in” period after a change of environment and owner. So normally the advice would be not to upgrade a cage in that first two weeks. But - a 20 gallon tank is really small for a Syrian hamster. They need quite a bit of floor space (but not too much height due to falls leading to injuries. They are really not good with heights at all- they can climb up but can’t get down again so tend to just drop and end up injuring themselves (sometimes quite badly if they land on something hard or sharp). The rule of thumb is they shouldn’t be able to fall further than 30cm max and even then shouldn’t be able to fall on something hard or sharp. Although a shelf or level is good, the maximum cage height shouldn’t be more than about 40 to 45cm and with a good depth of bedding to cushion any falls. 50cm tall means quite a few work arounds or very deep bedding.
So a cage topper isn’t a good idea. And as said above, you’ll need to work with what you’ve got for now. Make the best of the space on her current tank and provide plenty of out of cage time. Ideally on a secure hamster proof environment. Free roaming in one room can be good but hamsters can get into the smallest hole in the floor or wall or trapped places so careful checking is needed. If she’s not that hand tame with you, a playpen area is probably best at first (a sectioned off area). Some people use the dry bath tub for taming.
It sounds like your rabbits free roam though so I’m not sure how that would work. Maybe have her out on the bed? I used to put blankets round the edge as a barrier to slow up any escape attempts.
You’ll probably find a 28cm wheel will take up most of the space in a 20 gallon tank so you won’t be able to add much enrichment. Enrichment being - plenty of bedding, a house or nesting box , a shelf or level ideally and extra hides, tunnels snd toys. The main thing they need for nesting is somewhere dark where they feel secure and can build a big cosy nest. If there isn’t room for a large ish house then they sometimes build an open nest and pile substrate on top of it (like a kind of burrow). Or she may use the smaller house.
So in terms of cage upgrade you’d need to have a think about space - it’s difficult when you don’t have much space . I got a cage that was far too small for our first hamster, who developed cage aggression and bar chewing very quickly. I didn’t think I had space for an 80 x 50 cage but basically ended up rearranging the room - hot rid of a piece of furniture and replaced it with tall shelves so all our stuff was on shelves going up the wall - which provided more floorspace to fit the bigger cage! It was quite therapeutic actually - I was pleased to have created more space.
So you sometimes have to be a bit creative - but if there’s no room then there’s no room. If you have something like a desk, chest of drawers or kallax unit a cage could sit on top of those. And move the contents on top elsewhere. Kallax units have storage underneath as well.
It sounds like you’re in the US and good cages are hard to find (even more so during the pandemic) so most people use tanks or bin cages. There is one ideal cage that isn’t too expensive and not too big or too small - the prevue cage from Amazon - but I believe it’s been out of stock throughout the pandemic.
Most people say a 40 gallon breeder tank is the ideal size for a Syrian (about 90cm by 45cm) but that is quite large to fit in if you’re short on space. You might be able to make a decent sized bin cage to fit on top of a chest of drawers eg. Finding good sized bins isn’t that easy either - most are too narrow and slope in at the bottom. I personally think depth is more important than length if a cage isn’t quite big enough as they do need to move around and have floorspace - they’re ground dwellers and diggers basically.
A popular diy option is a detolf cage. An IKEA detolf glass cabinet tipped on its side with the door left off so it’s open at the top. And needs a lid making out of strips of wood and mesh. This is very long but sits on top of kallax units well which can provide a lot of storage underneath snd it isn’t that deep (but deep enough) so doesn’t stick out in a room too much snd basically just goes along a wall - if you have enough wall space.
If you Google “hamster detolf “ and click on “images” you’ll get the idea.
I found creating space can be expensive, if it means changing furniture, but you can get stuff second hand.
Ideally you want something with at least 75cm by 45cm floor space. Having said that people used to keep hansters in 60 x 40 cages with two shelves in when I first joined this forum. So the main thing is to create enough places to go and things to do and plenty of our big cage time and interaction (I used to get out hamster out on the bed with a few toys on it). They need to be quite hand tame for that or will just do a runner!
What are the dimensions of the 20 gallon tank? You might be better getting an 8”, 9” or 10” wheel for now, to take up less space in the tank so you can make the remaining space more interesting. But their basic needs and habits are nesting, foraging, and wheeling. Burying hoards. So scatter feeding is prinsbky best (you can give a bowl as well if there’s room and put some food in the bowl and scatter some - they need about a tablespoon full a day of a good muesli mix. Don’t get a pellet food. Harry or Hazel Hamster is fine. US members will know about alternative mixes but most of those need supplementing. The HH mixes contain everything needed - all the right nutrients, protein and vitamins.
Water bottle better IMO. But check it every day to make sure it’s letting water out. Bowls can get contaminated. And take up space. Industrial strength Velcro can be used to attach the bottle in the right place.
Some don’t
Don’t do daily or weekly clean outs - causes then huge stress. Just “spit clean” the pee area. Other than their pee they are not dirty or smelly. Don’t worry about poops - they eat those sometimes as well so removing all of them regularly is stealing! They aren’t dirty or smelly and like little hard seeds really - if they accumulate a lot then spot clean.
Don’t use any fluffy bedding, cotton, material (eg hammocks) - they chew and cab get intestinal blockages or threads cutting off their circulation (feet and legs tangled). Plain white toilet paper torn into strips is best for nesting material. Give plenty of nesting material in a heap and the hamster will pouch some to take to the nest. Just keep topping it up as it goes down.
Ideally don’t disturb the nest and hoard - unless pee’d on.
Don’t keep moving things around - they prefer familiarity and stability. Swapping out a wheel is ok. Adding new things is accepted - taking things away can lead to massive tantrums (unless replaced with something better!)
Female hamsters can be very active and quite maverick. Cardboard is your friend - they can chew it, destroy it and it keeps them busy. Cardboard toilet or kitchen roll inner tubes are good for toys (slit them down one side or they can get stuck). A tissue box is fine for a house or hide in a smaller area.
They won’t eat all the food you put out - they hoard most food and snack from their hoard/larder - so some needs throwing away from the bowl after a day or two but still always put new new food out every day (they ignore any good food that’s a day or two old for some reason). Change water every day or two. Check water bottle daily. They can die of no water for a couple of days.
Think that’s about all for now - I’ll have a look at current cage option availability!
Sorry for typos - on my phone and it keeps changing things I type!