ok as i'm sure most of everyone knows, the u.s had a massive heat wave issue. my tiny 50gallon pond hit a high or 98deg temp wise. surprisingly the baby molly in there is still alive. O.o however it's now holding in the low to mid 90's and i still don't feel good about putting my bf's new koi in there.

so for temporary they are in our living room in the 20 gallon tank. i want to know if this is an ok setup that i have for them. even if it's temporary.

they are 2 butterfly koi at 2" long bodies. the tank has a bare bottom, 3 fake plants in the center close together but enough space for them to swim through and 2 rock caves in one corner, below the filter and an airstone catty corner from it. there is also one floating plant. that i threw in for them to nibble on. leaving most of the tank bare and open for plenty of swimming room.

is this ok? or do they need more hiding places? they've been swimming like mad since they were put in. they only chill out a bit after they are fed. swimming slower. since the pond has a sand bottom do they need sand in the tank? i figured large pond fish more open space would be greater than dense decor. please correct me if i'm wrong

also trying to use the pond to grow some duckweed. it doesn't last long in any of my tanks. >.> will the koi eat the duckweed?