Steven Cyr
Member
- Joined
- Oct 11, 2016
- Messages
- 6
- Location
- USA
- Vessel Name
- Grace
- Vessel Make
- North Pacific 43 Pilothouse
I have struggled for years finding a holding tank treatment that would work through the hot summer months. After trying various liquid treatments over the years, I experimented with a popular powder called Noflex Digester. It seemed to work but it was expensive to use. I gave up on it because of the expense of using it in the proportions needed to keep the odors down. This year I decided to give it another go and bought three 1 LB cans of it, which cost me over 60 bucks. You have to use a lot of it to initially get the tank fairly clean, and for it to work properly. The dosage suggested is the absolute minimum, and you will likely need to use more, especially as tank temperature get warmer in the summertime. My final conclusion was that it did work better than all the other liquid treatments I had tried, but I still had to exceed the suggested dosage for it to work well. I am familiar with the head mistress and her recommendations, but my system just can’t freely vent enough air to keep oxygen levels up. I suspect the digester compound works so well because it produces oxygen in the tank to keep a good balance of aerobic bacteria working.
My issue with this product was paying so much for what was basically highly oxygenated laundry detergent. I tried to contact the company to see if I could by it in larger more cost efficient containers, but I never received a reply. Finally I decided figure out for myself, what is in it, and if I could come up with a compound that would work as well, but wouldn’t be putting money down the toilet. The following is the result of that investigation.
The SDS for the Digester product states that it includes approximately:
Sodium Carbonate Peroxyhydrate 40 to 60%
Sodium Carbonate 10-20%
C8-10 alcohols Ethoxylated Propoxylated 1-5%
These are the basic ingredients of laundry detergent but in much different proportions. Also to add more confusion into the formula, there are many different names for the same compounds. So let’s break this down.
1. Sodium Carbonate Peroxyhydrate is a technically more descriptive name for the same compound commonly known as sodium carbonate peroxide or sodium percarbonate. This is an environmentally friendly product used for a variety of things. It can be used to control certain vegetation in lakes while not impacting desirable plants and fish. Brewers use it to clean vessels used in beer making. When combined with water, it will break down into soda ash, and hydrogen peroxide which will further break down into water and oxygen. Oxygen is what you need to keep your “good aerobic bacteria” working in your tank. Pure Sodium Percarbonate is not cheap, but you can by it in 10 lb. buckets on Amazon for about $5.00/lb.
2. Next ingredient is sodium carbonate. It is also commonly known as disodium carbonate, washing soda, or soda ash. This is the base ingredient for powdered laundry detergent. It is also used in glass manufacturing and as a water softener. Arm & Hammer powdered laundry detergent is about 81% disodium carbonate (sodium carbonate). It also has about 7.3% Alcohols, C12-15, ethoxylated.
3. The third ingredient is ethoxylated alcohol. Ethoxylated alcohols are used as wetting agents and help to breakup greasy or fatty compounds. They help detergents work better.
These 2nd two ingredients are the basis of Arm & Hammer powdered laundry detergent.
Reading various discussion groups on this same subject, I seen the question, “what about Oxiclean?” Oxiclean does work using oxygen in the form of sodium percarbonate, but the concentration doesn’t come close to Digester. The SDS for Oxiclean states it is between 10-30% sodium Percarbonate, and 72% sodium carbonate. So this is a really poor source of sodium Percarbonate for the holding tank. Powdered laundry detergent with Oxiclean has even lees percarbonate.
So I began my investigation for a good source of sodium carbonate, that might already have the other agents like the ethoxylated alcohol and other surfactants, and agents that would assist in doing what Digester does. Living in USA, I was familiar with the industry leader, Arm & Hammer Company, in manufacture of sodium carbonate products so I began there. Arm & Hammer Powdered Laundry Detergent is what I settled on. The SDS states the following contents:
Disodium carbonate, 80.2 - 82.9%
Alcohols, C12-15, ethoxylated 6.8 - 7.8%
I purchased a 10 LB bucket of sodium per carbonate on Amazon and a box of Arm & Hammer powdered Laundry Detergent at Walmart. I blended my first trial batch at a ratio of 3 parts percarbonate to 2 parts detergent. That gave me a blend of approximately 60% sodium percarbonate, 32% sodium carbonate, 3% alcohol, and 4% other (which I believe to be mostly baking soda in the detergent.) I refilled my empty 1 lb Digester cans. I liked that size can for storage in the head. That blend worked pretty well, but the scent of the detergent was noticeable. It smelled like we were doing laundry after we flushed the toilet. Head odors remained under control and Pumpout were cleaner that previous. My next test batch was blended at a ratio of 2 parts percarbonate to 1 part detergent. That resulted in a blend that was approximately 66% sodium percarbonate, 27% sodium carbonate, 2.5% alcohol, and 3% other. I liked that even better, and that is what I settled on. The detergent scent wasn’t noticeable anymore, and the extra oxygen in the tank can only help. This isn’t an exact copy of the Digester formula, but seems to work as well or even better, at less than 25% of the cost. At $5.00/LB for the sodium percarbonate, and $3.00/LB for the detergent, the homemade blend works out to $4.33/LB.
With the cost being so much lower, I’m not tempted to under treat the tank and get into a stinky situation. Also it helps to spread the dosage over time to keep the tank oxygenated. I do half the daily dosage in the morning and half in the evening. That really works great.
The dosage for Digester calls for a tablespoon per person every two days. I found that didn’t cut it in my system so I had to double that in the summer. That meant one tablespoon each day per person. We are two on my boat so I use two tablespoons a day. One in the morning, and one in the evening. So far I am very happy with the results.
Just wanted to share what works for me!
My issue with this product was paying so much for what was basically highly oxygenated laundry detergent. I tried to contact the company to see if I could by it in larger more cost efficient containers, but I never received a reply. Finally I decided figure out for myself, what is in it, and if I could come up with a compound that would work as well, but wouldn’t be putting money down the toilet. The following is the result of that investigation.
The SDS for the Digester product states that it includes approximately:
Sodium Carbonate Peroxyhydrate 40 to 60%
Sodium Carbonate 10-20%
C8-10 alcohols Ethoxylated Propoxylated 1-5%
These are the basic ingredients of laundry detergent but in much different proportions. Also to add more confusion into the formula, there are many different names for the same compounds. So let’s break this down.
1. Sodium Carbonate Peroxyhydrate is a technically more descriptive name for the same compound commonly known as sodium carbonate peroxide or sodium percarbonate. This is an environmentally friendly product used for a variety of things. It can be used to control certain vegetation in lakes while not impacting desirable plants and fish. Brewers use it to clean vessels used in beer making. When combined with water, it will break down into soda ash, and hydrogen peroxide which will further break down into water and oxygen. Oxygen is what you need to keep your “good aerobic bacteria” working in your tank. Pure Sodium Percarbonate is not cheap, but you can by it in 10 lb. buckets on Amazon for about $5.00/lb.
2. Next ingredient is sodium carbonate. It is also commonly known as disodium carbonate, washing soda, or soda ash. This is the base ingredient for powdered laundry detergent. It is also used in glass manufacturing and as a water softener. Arm & Hammer powdered laundry detergent is about 81% disodium carbonate (sodium carbonate). It also has about 7.3% Alcohols, C12-15, ethoxylated.
3. The third ingredient is ethoxylated alcohol. Ethoxylated alcohols are used as wetting agents and help to breakup greasy or fatty compounds. They help detergents work better.
These 2nd two ingredients are the basis of Arm & Hammer powdered laundry detergent.
Reading various discussion groups on this same subject, I seen the question, “what about Oxiclean?” Oxiclean does work using oxygen in the form of sodium percarbonate, but the concentration doesn’t come close to Digester. The SDS for Oxiclean states it is between 10-30% sodium Percarbonate, and 72% sodium carbonate. So this is a really poor source of sodium Percarbonate for the holding tank. Powdered laundry detergent with Oxiclean has even lees percarbonate.
So I began my investigation for a good source of sodium carbonate, that might already have the other agents like the ethoxylated alcohol and other surfactants, and agents that would assist in doing what Digester does. Living in USA, I was familiar with the industry leader, Arm & Hammer Company, in manufacture of sodium carbonate products so I began there. Arm & Hammer Powdered Laundry Detergent is what I settled on. The SDS states the following contents:
Disodium carbonate, 80.2 - 82.9%
Alcohols, C12-15, ethoxylated 6.8 - 7.8%
I purchased a 10 LB bucket of sodium per carbonate on Amazon and a box of Arm & Hammer powdered Laundry Detergent at Walmart. I blended my first trial batch at a ratio of 3 parts percarbonate to 2 parts detergent. That gave me a blend of approximately 60% sodium percarbonate, 32% sodium carbonate, 3% alcohol, and 4% other (which I believe to be mostly baking soda in the detergent.) I refilled my empty 1 lb Digester cans. I liked that size can for storage in the head. That blend worked pretty well, but the scent of the detergent was noticeable. It smelled like we were doing laundry after we flushed the toilet. Head odors remained under control and Pumpout were cleaner that previous. My next test batch was blended at a ratio of 2 parts percarbonate to 1 part detergent. That resulted in a blend that was approximately 66% sodium percarbonate, 27% sodium carbonate, 2.5% alcohol, and 3% other. I liked that even better, and that is what I settled on. The detergent scent wasn’t noticeable anymore, and the extra oxygen in the tank can only help. This isn’t an exact copy of the Digester formula, but seems to work as well or even better, at less than 25% of the cost. At $5.00/LB for the sodium percarbonate, and $3.00/LB for the detergent, the homemade blend works out to $4.33/LB.
With the cost being so much lower, I’m not tempted to under treat the tank and get into a stinky situation. Also it helps to spread the dosage over time to keep the tank oxygenated. I do half the daily dosage in the morning and half in the evening. That really works great.
The dosage for Digester calls for a tablespoon per person every two days. I found that didn’t cut it in my system so I had to double that in the summer. That meant one tablespoon each day per person. We are two on my boat so I use two tablespoons a day. One in the morning, and one in the evening. So far I am very happy with the results.
Just wanted to share what works for me!
