How Can Reuse The Tank?

As those of you who read my thread already know, Poseidon passed on yesterday from some sort of fungus/fin rot thing. Despite being heartbroken I'm not one to dilly dally and I want to get the tank ready for the next addition, it's just too painful to look at and only see a few otos swimming about.
I have a BIG problem though, how can I add a new fish without risking it's health or my otos? I can not empty the tank and clean it out because
....
#1 Have you ever tried catching otos in a planted tank?
#2 I'd hate to have to uproot my plants.
#3 oto's need a cycled tank and emptying and cleaning a cycled tank would ruin the cycle it had.

My tank is also still full of the meds I added, but the otos look like they are doing well and aren't (yet, anyway) showing any signs of illness themselves::knock on wood::
SO how do I get it ready? I'm considering gettign a fish off aquabid (ie. It'll be expensive) so i can't risk it's health. What should I do?

Also for some reason th pH dropped, I'm not sure if it is my tap water that changed or jsut the water in the tank, I've heard the chemicals that change pH do more harm than good, so how do I change it? I can't not because it is already down to 6.0.

What is the P.H.? What was it before? What is tank is it? if the ottos seem fine I'd maybe wait a week or two and see if they show any signs of illness and if they don't the I'd say the tank would be fine to put another betta in. Good luck.

Hmm, for now I'd reccomend frequentish water changes along with carbon in the filter to get rid of the meds, see what happens with the pH (whether it returns to normal). The disease *should* only spread if the otos are stressed, keep the water clean and you should be OK. Just keep an eye on the new betta when you get him.

A pH of 6.0 is fine as long as it's consistant. I would do several water changes like every other day and see what happens with your water parameters. And, like suggested before, make sure you have carbon in your filtration system to clear out the meds in the water.

i know its hard with an empty tank, but if you are considering buying an expensive betta you really should wait and watch the ottos for another week or two and see how they go. other than that, carbon and water changes are a good idea to get rid of the meds and whatever diseases your betta left behind.
on the note of stress, if the ottos are only going to get sick if they get stressed and you do order a nice expensive betta, be sure to quarantine him and when he is no longer stressed from his journey, etc. then put him in with the ottos.

Yeah thats what I said about the ottos.

all i have to add is that i'd wait for a month or more instead of just 2 weeks.

think of it as the perfect opportunity to perfect your plants.

Thanks for all the advice guys! The pH is usually 7.2, which is why I can't figure out what on earth happened, unless my testers are going nuts. I'll try to get a new filter cartrage tommorrow and do a water change as soon as I can warm up enough water (the tank is already low because I took alot out when Poseidon got sick). So far the otos seem happy and healthy. I wonder, can Maracyn change the water pH? It was after I added that, I noticed the drop, not that I'm one to test too often. It has always stayed constant before. I guess I'll wait until I'm confident enough and hope for the best.