Guinea pigs are relatively large. The adult weight is approximately 1 kg, length is about 25 cm. So it means they are way bigger than a hamster, and a youngster multiplies its size several times. Thus, the place that seems large enough for young piggies could be seriously small within a few months.

 

The minimum for two sows should be a 120 cm cage, for boars it must be at least 140 cm. This is the bare minimum, the larger the better. In addition to this basic cage you must provide them a place to run every day. (Obviously if your cage is large enough, you don't have to let them out.)  When they are outside make sure the environment is safe for them. Most indoor plants are poisonous, they should not have the chance to chew them, it could lead to a very painful death. Do not forget about the possible falling leaves either!
They can chew electric cables and that could cause horrible accidents. You must be sure that the area they use is free from predators as well. Using fences can make this whole process much safer.

 

You can buy them wired cages (zooplus has a great variety and it is way cheaper than pet stores) or C&C enclosures. The latter must be ordered from the UK, Kaveecages is a possible source.  

 

Bedding

 

There are plenty of options, a lot of them works very well, it is more about personal preference. Here is a table about the most common ones and a description of each of them.

 

Bedding Description
woodflakes Absorption is good. Soft, doesn't harm the feet. It can be dusty which isn't good for anyone.
wood pellets Absorption is excellent. Rough, hard, there must be a comfortable second layer on top of them.
straw Absorption is week. Better to avoid.
paper bedding It can be a solution for allergic owners or cavies. It comes with a hefty price.
fleece Soft, comfortable, it doesn't cause allergy. It doesn't absorb urine by itself, there must be a second, bottom layer for that purpose. You must swipe the poop in a daily basis. You have to wash it.
Guineadad fleece It contains the hygroscopic material in itself. Expensive. Sweeping and washing is necessary.
Microfibre bath mat The surface is fleece, inside there's a hygroscopic layer. You can shake them out to remove the poop. You must wash the mat.

 

Equipments

 

Guinea pigs are prey animals, they have a very strong urge to hide. They only feel safe if they have the option to surrender. It doesn't mean that they are constantly hidden, but the option itself makes them relaxed.
So, the most important accessories are hide-outs. There are wooden or PVC houses, textile covers. Always check the wooden materials. Lower quality houses can contain protruding nails.
We can use tubes as well. The large PVC tubes for sewering are exceptionally good choices, cavies love them. If it is equipped with a rubber seal, you have to remove it first, otherwise your cavies will.
Hammocks are also popular equipments. It requires a certain mentality, not every guinea pigs are into them, but even they can hide under them.
When your cage isn't very huge, lofts could improve the situation. However, please note that surfaces in different levels aren't as beneficial as single large areas.

 

Water can be offered in bowls or water bottles. The latter should be sanitized from time to time by boiling in water (if you have a plastic one, make sure it can bear the temperature). If using bowls, clean them several times a day, poop often lands in them.
For food heavy ceramic bowls are the best choice, they tend to turn the lighter objects upside down.

Hay racks are widespread equipments, but they are not suitable for guinea pigs. It is not comfortable for cavies to use them, they naturally graze from ground level. Thus, you should place their hay to the ground. It means more waste, however if you use hay boxes, they can function as their toilet as well. At least for urine, unfortunately you can still expect them to poop everywhere. Hay boxes could be anything that has low sides, so that the hay stays in while the animals can go in and out. 

 

To reduce the tensions between boars you must provide two of every accessories. For female cavies it is not that important, but make sure they have enough place to hide. Also, if you have a group, it is adviseable to use several bowls and bottles to avoid queues.