Algae in Freshwater Tank

Dont store water in the tank except when your actually using it. Lots of bleach and sanitize the system.

Time for the Bleach treatment.

Mix 1/4 Cup per 15 Gallons of tank capacity until tank is full. Turn on pump and open all water valves to distribute the mixture. Turn off valves and pump and let sit for at least 12 Hours.

Run more solution thru lines after 12 hours and then drain tank and refill with fresh water. Flush lines and tank until Bleach can no longer be smelled, usually 3 times for my trailer.

If your tank is inside the vehicle and you have access to the top of it, you can cut a hole in it and install an appropriate size deck plate from a marine vendor.
That's what I do in all my accessible tanks in order to clean them. You would not believe what the bleach doesn't get out but ol' elbow grease will.

I do not have access to the tank from inside.Only way to get the bleach in to the tank is through external water filling outlet.Now what is the best way to get the bleach in the fresh water tank.I mean should I have to connect a pipe to external filling hole and pour bleach with hand or there is another way to do it.

You should first sanitize your freshwater hose thoroughly; it may be filled with algae too. Mix about 1 ounce bleach in a gallon of water. Hold both ends of the hose up in the air, pour the bleach in one end, and screw them together. Slosh it around and let it set for about 12 hours. Then dump it out.

Make up a fresh batch of bleach in the correct amount for your system (1/4 cup bleach for every 15 gallons of tank capacity, plus the water heater volume). Put the bleach in about a quart or more of water. Put the hose on the fill, pour the bleach in, and then connect the hose to a spigot. Fill the fresh tank.

Open all the faucets, hot and cold and run through until you smell the bleach from each one. Be sure to run enough hot to fill the water heater. Dont' forget the outside shower if you have one. Then let it stand 12 hours or longer.

Drain the fresh tank and fill it with clean water. Run through the entire system until no more bleach smell. This may take a couple of drain/refill cycles on the tank.

At this point you may have to clean the filter again.

If you routinely fill with non-chlorinated water, you may have to sanitize often.

I bleach mine twice a year but left some well water in it a little too long. It had small black clumps of crud coming out the drain. I ended up removing the tank and put cleaner and a bunch of nuts and bolts in it and kept tipping the tank from end to end and round and round to scrub the black line out of it.

The inside of the tank is irregular shape so it wasn't easy.

1320Fastback wrote:
Time for the Bleach treatment.

Mix 1/4 Cup per 15 Gallons of tank capacity until tank is full. Turn on pump and open all water valves to distribute the mixture. Turn off valves and pump and let sit for at least 12 Hours.

Run more solution thru lines after 12 hours and then drain tank and refill with fresh water. Flush lines and tank until Bleach can no longer be smelled, usually 3 times for my trailer.

Only fill the tank half full then drive it to get a good slosh going.
The hydraulic pressure will clean it much better.
Also if you are on a well only fill when using the motor home then empty when you return.
Or there are formulas for how much bleach to add to treat for useable water.

bill257 wrote:
I do not have access to the tank from inside.Only way to get the bleach in to the tank is through external water filling outlet.Now what is the best way to get the bleach in the fresh water tank.I mean should I have to connect a pipe to external filling hole and pour bleach with hand or there is another way to do it.

I have a coachmen Class C also, so I assume the water fill is like yours. I poured some bleach into the fill hose then attached it to the camper water fill and the other end to the house spigot,then turned the water on. Worked pretty good. Gary