ich- water change then medicate again, or wait?

[silvermoon]

We recently got 3 new smaller clowns from an acquaintance who couldn't keep them any more. She had them about 2 months and they had never displayed any signs of illness. So we didn't quarantine them or pre-treat before adding them to our new 55 gallon.

Stupid, stupid.

Last night I wasn't sure, but this morning one of our bigger (3.5-4") clowns definitely has tiny white spots all over. One of our tetras also looks really bad, breathing heavy.

Of course I notice while I'm feeding them, which is right as I'm about to leave for work. I checked the Ich thread but had no time to do a water change and gravel vacuum before I left.

So far we have:
-removed the filter charcoal
-Turned up the heater (tank was at 80, set it to about 83 for now)
-Added a half-strength dose of RidIch (formalne/malachite green)

Water params yesterday were 0 ammonia, 0 nitrites, 20ppm nitrate, pH around 7.5. Don't remember the hardness or the rest. Tank has many air stones with lots of splashing and bubbles.

My main question is this: The recommendation is to do a 50% water change, vacuum the substrate and THEN add meds. Should I do a water change when I get home or just vacuum the gravel and leave as much of the medicated water in as possible? Do the 50% change and add a quarter dose (half of half) of meds afterward?

The clown is acting healthy and was still eating and moving normally. We might lose the tetra. None of the other clowns have symptoms that I see. It might even be our alpha clown who is ill, the 'big three' are so similar in size it is hard to tell them apart unless they are all next to each other.

[chefkeith]

I've never used rid-ich before, but I found these instructions-

http://www.novalek.com/kordon/ridich/index.htm

" Perform a partial water change of at least 20-25%. Repeat water changes at 20-25% before each re-treatment with Rid·Ich+........

Treatments may be repeated as often as every 6-12 hours (depending upon the severity of the particular disease and the tolerance of the diseased fishes). Treatment should be repeated no less than every 24 hours"

[Diana]

Water changes, and especially gravel vacs remove a lot of the Ich organisms from the water. I would be doing daily thorough gravel vacs, and not worrying so much about the volume of the water change, and re-dose the meds at that time.

[plaalye]

I don't have clowns but I've used Rid-ich sucessfully and with no losses. I have Khulis, Kubotai,Striata, Sewelia, Gastromyzon, cardinal and neon tetras. I follow the directions on the bottle, full strenghth.

[silvermoon]

Thanks for the suggestions. So far all the fish are hanging on, even the 'bad' tetra was eating heartily and chasing its fellows around.

Of course, I forgot that our sink attachment to the gravel vacuum broke last weekend, so had to run out and get another one this morning. The timing on this is just awful. I'm having oral surgery this afternoon to remove wisdom teeth, so I'll be out of commission the rest of today and probably tomorrow.

Trying to press upon my husband the importance of vacuuming and changing out some of the water.