Hello DehvidWV.
Congrats on the tank upgrade for your fish! I think most importantly is to keep all of your filter media wet. This will help you to maintain your cycle. You can use the filter/filters from your 29g on your 55g or you can transfer the filter media into the 2 Penguins. You can place the gravel from your 29g tank in "NEVER SEEN SOAP" nylon hose and place it in your tank. The more you add the better off your cycle will be. By using the nylons you can remove it after a few weeks and it won't keep you from using the gravel/substrate you choose. Leaving the nylon filled hose in the tank for a few weeks will help prevent you from going into a mini cycle, and give your new substrate time to build it's own colony of good bacteria.
Check the
pH levels in your 29g tank and compare it to the new water that will be going into the tank. You want it to be as close as possible (it would be better that the new water have a higher pH than lower pH). Sudden changes in pH levels can be fatal especially if it's lowered to quickly.
Also make sure your water temperature in the tank and the new water are as close as possible as well. Sudden changes in temperature can stress the fish and lead to
ICH.
I recommend adding 1/2 the water from the 29g tank....add the fish so they don't have to
acclimate to a new pH right off the bat. Then add the new water with the
chlorine removed. The reason I only suggest 1/2 is because the good bacteria in your tank is not free swimming but attached to all surface areas within the tank (mainly filters and substrate). By only adding half and then using new water it will be like a big
water change and not a complete shock to your fish.
I suggest not adding any additional fish for several weeks until the 55g has time to establish more bacteria. Keep an eye on your
ammonia,
nitrite,
nitrate levels and don't forget your regular water changes. Regular water changes will help you to maintain steady pH levels.
Best of luck and keep it fun! I hope you can share some photos when you're done if you have the means.
Ken