Cleaning a fresh water holding tank

[bgallinger]

I have a scum line inside the fresh water holding tank and I want to remove it. The tank is made of a plastic material and holds 70 gallons. At present the only access is a 2" dia. hole where the tank volume sender sits.
Is there a cleaner that will remove the scum line?
Can a larger hole be cut and then re-cemented after cleaning?
Thanks in advance!

[Pete7]

Does it have any baffles in it? I have used these before and if glued in with sikaflex would give you room to get inside better. There is a clear lid version which will be good to see into the tank. They have an o ring seal so stop any leaks.

Access Panels|tank|hatch|boat|water|TCL4

We currently have one of those clear dinghy inspection hatches but its a GRP tank, just not sure if it would work in plastic.

Pete

[bgallinger]

Originally Posted by Pete7

Does it have any baffles in it? I have used these before and if glued in with sikaflex would give you room to get inside better. There is a clear lid version which will be good to see into the tank. They have an o ring seal so stop any leaks.

Access Panels|tank|hatch|boat|water|TCL4

We currently have one of those clear dinghy inspection hatches but its a GRP tank, just not sure if it would work in plastic.

Pete

Thanks for the link Pete7! My tank does not have baffles, but a 7" dia. access would really help!

[belizesailor]

You could try cleaners for brewing which are good for cleaning tanks in similar situations. One product in particular is great for similar brewing situations: PBW.

https://www.amazon.com/Five-Star-PBW.../dp/B0064O7XBA

Assuming an HDPE plastic or similar I expect it would be fine, but you should confirm.

A little PBW mixed with water and left to soak overnight removes even really stubborn stuff.

[gonesail]

you can cut a 6" or 8" hole and use one of these by Seabuilt.

[peghall]

If there's a scum line in the tank, you can bet there's also scum and slime in the plumbing. Recommissioning the system solves both problems without the need for any "surgery" to add a port to the tank. I've posted the instructions here several times and have also included them in my book (see link in my signature...just click on the title).


--Peggie

[Shrew]

At the risk of not letting Peggie have the last word on this.......bleach.

I had the same problem, including a horrible odor in the freshwater. I did three treatments of bleach. I used about 1 cup of bleach per 60 gallon tank. I thought I had it in two treatments, but it returned the following season. The third treatment I used 2 cups per 60 gallon tank.

The third treatment appears to have solved the issue. That was 2 years ago.

[MJH]

Originally Posted by bgallinger

I have a scum line inside the fresh water holding tank and I want to remove it. The tank is made of a plastic material and holds 70 gallons. At present the only access is a 2" dia. hole where the tank volume sender sits.
Is there a cleaner that will remove the scum line?
Can a larger hole be cut and then re-cemented after cleaning?
Thanks in advance!

My boat has two 100 gallon stainless steel tanks. As best as I can remember when I purchased the boat in 2007 I added one gallon of bleach per tank and top them off overnight, then drained them again and refilled. Some months later when the boat was hauled (elevated) I drained them again, opened them up and scrubbed them with a NEW toilet brush while having a spray hose and a drain hose connected. The evidence of the need for cleaning came out of the drain hose onto the asphalt paving of the marina.

So, no matter what you put in to disinfect you still needs to scrub the inside walls and creases to get rid of the evidence of it being there.

Good Luck.

~ ~ _/) ~ ~ MJH

[mikehmc]

Originally Posted by peghall

If there's a scum line in the tank, you can bet there's also scum and slime in the plumbing. Recommissioning the system solves both problems without the need for any "surgery" to add a port to the tank. I've posted the instructions here several times and have also included them in my book (see link in my signature...just click on the title).


--Peggie

Hi Peggy Hall! Glad to See You! We are trying to find our copy of your book (its on one of the boats). But I looked at online index, and it didnt seem to have a chapter for flushing drinking water. can you post instructions again? we just boat a boat with 150 gallon water tank and lots of plumbing. This reminds me to tell everyone what great success we have had from your book.

Cheers
Mike

[peghall]

It's in Part V "To Everything There Is a Season." "Fresh Water Maintenance" begins on page 59.

If you can't find your hard copy, the Kindle edition is only $9.95 and you don't need the Kindle tablet, just the Kindle app which you can get for both iphone/ipad and android tablet/phone for free.

--Peggie

[Hunky Dory]

Bleach works, but takes time to clean out if overdosed. RV and Marine stores carry products to clean and sweeten tanks and lines. Camco make Taste Pure apply at 29 ml. per 75 laters. eliminate taste of plastic metal, sulphur and eliminates algae build up. Camco also sell Spring Fresh in 3.78 literals container. Captain Phab has Purge Tank Cleanser.

[Lambretta]

Originally Posted by peghall

It's in Part V "To Everything There Is a Season." "Fresh Water Maintenance" begins on page 59.

If you can't find your hard copy, the Kindle edition is only $9.95 and you don't need the Kindle tablet, just the Kindle app which you can get for both iphone/ipad and android tablet/phone for free.

--Peggie

I cannot recommend this book enough ...... every yacht with a head and/ or water tank should have one. The key thing for me with Peggie's book is prevention is better than cure

[mjgill1]

Originally Posted by Lambretta

I cannot recommend this book enough ...... every yacht with a head and/ or water tank should have one. The key thing for me with Peggie's book is prevention is better than cure

Purchased!

[Lambretta]

Originally Posted by mjgill1

Purchased!

It really is a treasure trove of info!

[peghall]

Thank you!

Fwiw, title (my publisher's idea) is a bit misleading...'cuz although it does deal with every source of odor on a boat and how to cure, or better yet PREVENT 'em, it's actually a comprehensive "marine toilets and sanitation systems 101" manual that explains the laws, describes all the types of systems and how they work, and will help you learn how to operate and maintain your system to prevent 99% of problems instead of having to cure 'em.... 'cuz prevention is always cheaper and easier than cure, and you get to do any preventive maintenance on our terms when it's convenient...the need to cure a problem never happens when it is! And I'm always glad to answer any questions it doesn't.

--Peggie