Black Gunk in Freshwater tank

[BLIGHT]

After a year having the H35.5 on the hard we are prepairing it for use again. Noticed that black gunk must have formed in tank or supply line to tank. The gunk will clog the main water filter. So how can the tank be cleaned? I have not found a way to get to get to the tank but know there is not an inspection port on the tank.
Thanks
Bob Pulyer

 

[JamesG161]

What is your tank made of? Aluminum or Plastic?
Jim...

 

[BLIGHT]

Plastic type of material

 

[JamesG161]

They can be chemically soaked and cleaned. Others will suggest bleach, I like Hydrogen peroxide that bubbles.
You may have to jet it to hydro blast the bad spots.
I have a nice tool that side jets, flexes and can be inserted through small holes, level sensor ports, etc.
http://www.ebay.com/itm/like/121578223649
Very powerful 90° Angled jet with a shut off valve at hose connection.
Jim...

 

[JamesG161]

Wrong link... this is right and the valve is BLUE.
http://www.ebay.com/itm/Hayward-EC2...0475b2&pid=100338&rk=3&rkt=14&sd=121578223649

Jim...

 

[BLIGHT]

Thanks I have not heard of the Hydrogen Peroxide method but it sounds like a winner. The method that I have heard of was first to use detergent then flush. Then using bleach and letting it sit for least 12 hours to clean tank. Of course both are diluted. Using the blaster method I have to find out how I can get into my tank since its was installed first then built around. At the present time the only port that can be seen is the 1/2" exit port that has a right angle fitting that connects to my main water line. Of course, and to make it even more difficult the fitting is located close to the bottom of the tank and the tank support inhibits the unscrewing of the fitting.
I'll have to make another trip to the boat to investigate how to remove the plywood that covers the top of the tank to see if I can even address the blasting from the inlet or vent ports. I guess a viewing port can be installed?
Thanks, I'll let you know what I find. I like that wand that you mentioned. Is it flexible? I have a blaster fitting for a hose that might work if I can get in the tank.
Thanks Bob

 

[MitchM]

I'd be tempted to put an access port in to the top of the water tank that would allow a good pressure wash. the folks who sell the plastic water tanks have various kits and fittings ("port hole' type fittings) that allow good access. our freshwater tanks have always had these, and it's very simple to keep tanks clean once there is good access.

 

[JamesG161]

Hydrogen Peroxide method but it sounds like a winner

Here is one even made by Clorox®..
https://www.amazon.com/Clorox-30829...443&sr=1-8-catcorr&keywords=hydrogen+peroxide
You don't need Food Grade or Medical. Since this is killing the gunk and not purify.
BTW there are cheaper grades of H2O2 (hydrogen peroxide)
Look for the concentration on the bottle first. I can get mine from a local Sanitation Chemical supply house.
Benefits of peroxide, it makes Water and Oxygen, as it disinfects.

I don't store Chlorine bleach on my boat. I use medical H2O2 to assure drinking water is good to drink (in a pinch).

The best access to your water tank interior is your level sensor (normally Hunter design has access to top mounted sensors).

Once I got my brand sensor (WEMA) name, I found out the way it is removed by unscrewing (not the backing flange screws on the tank). I can inspect the interior with a light and or this...
http://www.harborfreight.com/digital-inspection-camera-61839.html
I have found this camera has WAY more valuable tool than I first thought. Behind walls, under tanks, around corner, etc.

Wand...
It is flexible , about 3' long, and will bend and easy 30°, my hand gets tired holding the "blast" jet back force.
Many of Hunters tank designs are available on their site now.
Jim...

 

[JamesG161]

first to use detergent then flush

Not in my water tank.
Hmmmm...
Laundry detergents are meant for specific reasons, normally cleaning of clothes.
If you use them, do it after H2O2 or bleach, since trace detergents consume you disinfectants.
After them....

Rinse, Repeat, Rinse, Repeat, Rinse, Repeat (at least 3 times)

Detergents are not meant for human consumption.

What was the olden times punishment for cussing? Wash you mouth out with Soap.
Jim...

 

[BLIGHT]

This is great, now I know that another trip to the boat is in store very soon. It would appear that the solution is to install a access port on the top of the tank and use the H2O2 instead of the bleach while skipping the detergent. Also, some type of blasting appears to be well advised. So onwards to finding the Hunter secret for removing the V berth plywood to access the tank. Once there check to see if a access port is there, probably not, my Hunter is a Legend 35.5 1989. Then check if an access port can be installed and if so get it done.
Thanks to All I'll let you know what I find.

Bob

 

[Allan Frey]

>Laundry detergents are meant for specific reasons,
You use a low suds detergent sold to wash dishes by hand in the sink, laundry detergents are not suitable.

allan

 

[JamesG161]

You use a low suds detergent sold to wash dishes by hand in the sink,

And if you use them, like your dishwasher, hand washer....

Rinse, Repeat, Rinse, Repeat, Rinse, Repeat (at least 3 times)

That is a laboratory procedure, other than they use distilled water.
Jim...

PS: I hated drying dishes by hand.

 

[pateco]

I am a brewer, and regularly use Iodophor for sanitizing my brew tanks and kegs. As a brewer we want no foreign organisms in our equipment as they can really mess up a good beer. Iodophor is a very common no rinse sanitizer used in brewing and the dairy industry. One of the main benefits of Iodophor is that if used in the recommended concentrations, it leaves no flavor or odor on the surface. Has anyone tried this for their fresh water tank(s)?

Iodophor Wikipedia

 

[thinwater]

Be advised that H2O2 is not a water disinfectant at any practical dosage and is not approved for water treatment by any authority that I know of (and I have looked). A few bottles from the drug store won't do anything much.

Bleach is the EPA, ANSI, and WHO standard for good reasons.

Also, without access for mechanical cleaning your prospects are poor. Disinfectants generally cannot penetrate accumulations, and there MUST be sludge in the tank if it is clogging filters. Would you rinse dishes in bleach but not scrub them? Unlike city lines, you do not have continuous chlorination. Without an access for proper cleaning, the tank will probably remain a scary cesspool, suitable only for deck cleaning. I would bite the bullet and do this right.

http://www.practical-sailor.com/blog/Decontaminating-a-Tainted-Water-Tank-11717-1.html

 

[Gunni]

Good reason to never dump antifreeze into your water tank - it is a nutrient for bacteria. On the other hand you have consumed a lot of water that came from pipes with 'black gunk', however it was killed. Peroxide in the concentrations available to the consumer will not alone kill the bacteria. Remove the water filters/screens. Mix up a shock treatment with unscented household bleach 3 cups/100 gals fill the tank and run water through all taps until you smell the chlorine, shut down the system and let it sit for 12 hours. Turn it back on, and empty the tanks, you should smell little chlorine because it has oxidized. Refill the tanks and add 1 teaspoon of unscented household bleach / 100 gals of tank volume. That is your maintenance treatment. Do that Everytime you refill. More is not better, stick to proper chemistry, or you will damage your plumbing and your body.
More:
http://www.cdc.gov/healthywater/emergency/drinking/disinfection-cisterns.html

 

[JamesG161]

Be advised that H2O2 is not a water disinfectant at any practical dosage and is not approved for water treatment by any authority that I know of (and I have looked). A few bottles from the drug store won't do anything much.

Do as you wish. At least on my boat, I rarely drink my fresh water.

I use medical H2O2 to assure drinking water is good to drink (in a pinch).

I prefer can or bottled drinks.

@BLIGHT happy de-gunking...
Jim...

PS: My boat survival kit has these...
https://www.amazon.com/Potable-Aqua...id=1465860026&sr=8-2&keywords=purifying+drops

 

[BLIGHT]

Everyone Thanks
I finished up today in the rain and now its just like a new tank. Once I got the plywood cover off the V berth where the tank is housed I found that, naturally the tank did not have an inspection port. So another trip the marina store to pickup a 6" Beckson Screw Out Deck Plate plus the goodies to secure it. Cut out the tank on the top and installed the plate. Checked inside and there was still black Gunk stuff floating around while some was adhered to the sides. Used a Sweeper Nozzle to blast the crud off the sides then used a wet vac, https://www.amazon.com/Nelson-Brass...22905&sr=8-7&keywords=brass+water+hose+nozzle , to remove the gung along with rest of the water. and checked my tater filter to make sure it was clean. I used the artical that Thinwater offered to get the correct mixture of bleach adn general instructions. I filled the tank and ran the water throught the all the outlets till I smelled bleach. I left it that state till the next day then emptied the tank and refilled and flushed again. The tank is now as clean as the day it was installed. I did not fell that I needed to use the HP to rid the tank of the bleach smell.
Thanks to All for turning a gunky tank into a sparkling one.

Bob

 

[skunther]

Bob; how were you able to get the plywood off to access your v berth? In my H35.5 the plywood is covered by hanging lockers, making it impossible to remove without cutting it. I still want people to be able to sleep there, so I am wary to cut. I need to get in there to change my water tank sensor though.
How did you do it?

Everyone Thanks
I finished up today in the rain and now its just like a new tank. Once I got the plywood cover off the V berth where the tank is housed I found that, naturally the tank did not have an inspection port. So another trip the marina store to pickup a 6" Beckson Screw Out Deck Plate plus the goodies to secure it. Cut out the tank on the top and installed the plate. Checked inside and there was still black Gunk stuff floating around while some was adhered to the sides. Used a Sweeper Nozzle to blast the crud off the sides then used a wet vac, Amazon.com , to remove the gung along with rest of the water. and checked my tater filter to make sure it was clean. I used the artical that Thinwater offered to get the correct mixture of bleach adn general instructions. I filled the tank and ran the water throught the all the outlets till I smelled bleach. I left it that state till the next day then emptied the tank and refilled and flushed again. The tank is now as clean as the day it was installed. I did not fell that I needed to use the HP to rid the tank of the bleach smell.
Thanks to All for turning a gunky tank into a sparkling one.

Bob