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I just got back from the Keys and need to decontaminate my Ballast Tank before I put it in my home port. I can't find anything on the Forum. Can somebody point me to a thread or make a suggestion how to kill any hitch hikers?

Chlorine. Tabs kill almost everything. You may have to break them into small pieces to get them in the vent hole. That's what I do.

Sounds like it's too late, but you really need to do it while the tank is full, preferrably some time before you leave the “contaminated” water. Add the chlorine to the full tank, let it do its job, say overnight at least, then drain it at the ramp when you pull it. More chlorine will require less time for a good kill; less chlorine will require more time.

Any remaining water (and there is always a lot that stays behind, even if you drain at a steep ramp, I confirmed this with a scope) should then have been sanitized for entering the new waters.

You can't decontaminate effectively unless the ballast is full, and filling it in the “new” waters carries the risk of contaminating it, but, you don't have any other easy options now. (Fill with a hose???)

A tablet will do the job, but requires time (days to a week, or more) to dissolve and disperse, and has the potential to burn (it's a VERY strong oxidizer) the known-not-to-be-chemical-resistant polyester if it is not agitated and moved around enough.

There is less risk going from/to salt water from/to fresh water because invasive species are usually fastidious and confined to either one or the other of the environments, and not both.

I prefer liquid chlorine ("bleach"), and a quart or litre to a full ballast will give you an effective kill within a day, assuming adequate wave movement for mixing. Unless your tank is severely infected by a thick buildup, then, increase the time and concentration.

Liquid pool shock (sodium hypochlorite) will do as well, use half as much of it. I use a 1l maple syrup HDPE (chemical-resistant) bottle that I pre-fill at home with the liquid pool shock, then just dump the whole container in (which is half full).

I keep the cut-off top of a 2l pop bottle (which fits in the fill hole and prevents splashing of the liquid chlorine in the fill bowl) in a small bucket in the bow storage area to use as a tall funnel. I run a bit of water rinse after the liquid chlorine to keep things neat and tidy. No muss, no fuss, all clean and rinsed, it all goes back into the bucket when I'm done, for the next time.

Also - you don't want to splash that stuff around; if you are prone to, and have the time, then the tablet might be the better choice.

- Brian.

Oh right, the ballast is empty and boat on trailer.

Ok, close the aft valve, bust up a couple of chlorine tabs or dump a quart of bleach in there. Fill it with a garden hose from the vent.

You can also open the aft valve and let it dry out for a couple of weeks.

Hey Russ - The ballast a tank will take years to dry out, a LOT of water (the amount surprised me) remains trapped by the half-bulkheads (you can see them, and the trapped water, with an inspection scope) that cross the bottom of the tank. After draining on the ramp until it stopped, and then being bow-high and open in dry storage all season, water will still be coming out (gallons each time) whenever you start, stop, or go around corners. A few weeks back I followed my boat when my sister trailered it for 30- 40 miles and after all that, there were still litres of water gushing out from the gate valve after every turn, stop or start. It will likely be the same on the return trip.

After that I conclude that only very heroic measures will actually get the ballast dry, so I'm not going to waste time trying - the mission is to just get "most" of the water out. (No reasonable amount of fan running (well, maybe several years, but certainly NOT a season) can possibly evaporate all those gallons of water).

-B.

RussMT wrote:
Ok, close the aft valve, bust up a couple of chlorine tabs or dump a quart of bleach in there. Fill it with a garden hose from the vent.

You might want to reverse the order. Fill from hose first, then bleach. Or better yet, half water, then bleach, then remaining water (so you get good circ).

Strikers : Glad You made it Home....how was the trip Texas Parks and Wildlife recommend the bleach and flush method....even going from one lake to another oh well Later. Ron.