Sea Monkeys Rule!

I have 3 tanks of sea monkeys.  Two of them are  just less than a week old and I can still hardly see them. 

My Mars tank looks cool but is not so great for veiwing the little ones.  We moved the oldest family into a magic castle tank and it is the best for veiwing (just ask my 4yr old) The last tank is a cheap ocean zoo and it works fine other than the sea monkeys are just so small. 

I do have them all on my desk with a heat light going through the night just to help with the cold.

Unfortunately the cold is going to slow them down quite a bit. It would be a good idea to place a thermometer next to the tank so that you can monitor the water temperature. If the temperature is still on the low side, you can move the lamp closer to the water if it is to warm move it further away. What type of lamp are you using? Halogen lamps are the best IMO as they add a lot of warmth like the older incandescent light bulbs did, compact fluorescent lamps and the new LED lamps add very little heat at all and so are a good choice for summer.