In that case, you would probably get an ammonia spike (if the rocks are not yet cured). If you are concerned, get a Rubbermaid tub and place the them in there with a powerhead or at least some airstones. Do a water change every other day. Or, you could test the water they are curing in. If you have a spare skimmer, you could even set it up to skim the curing tub.