The Tank › Aluminum Hydroxide sediment problem
- September 29, 2007 at 1:18 am #7194Doug_MummaParticipant
The problem – when I opened the drain valve to remove any sediment from the bottom of the water heater, the water had a milky-cloudy appearence. Initially I thought it was entrained air, but after letting it sit for a while, the milky-cloudy material settled to the bottom of the bucket as a layer of gel, so to speak. This has happened before, but I simply drained the entire hot water heater and started fresh.
The situation – This hot water heater is located at my mountain cabin which we only visit once a month or so. The hot water heater (a Reliance 40 gal propane fired with an aluminum anode ) is about 2 years old, but this problem had occurred with the old heater. That heater also had problems with popping sounds. There has been no problem associated with odor. This is a community water system supplied from 3 wells and is untreated. It has a fairly low hardness of 87 ppm. A further check with the water testing company revealed pH readings from the latest tests were 7.26, 7.32 and 7.5
Conclusion – After much searching of the Internet, including the manufactures web site, I conclude that the problem is the high pH of the water reacting with the aluminum anode rod which causes an aluminum hydroxide gel material to form. The problem is probably enhanced due to the low use of the hot water heater.
Solution – Since I cannot easily control the pH, it would appear that the problem should be reduced or eliminated if I change the anode rod material from aluminum to magnesium or zinc-aluminum.
Question – Which rod material will perform best under high pH conditions, magnesium or zinc-aluminum?September 29, 2007 at 3:13 am #7195Randy SchuylerKeymaster
You have correctly diagnosed your problem. The solution is a magnesium anode rod. The aluminum/zinc is 92 percent aluminum, so you’ll still have a significant amount of sediment from it. Magnesium corrodes differently from aluminum and throws off much less corrosion byproduct.
Randy SchuylerOctober 2, 2007 at 9:35 pm #7211
How did you know that the sediment was aluminum hydroxide?
I am having problems with random clothes fading in blotches after washing and even the rug next to my shower has faded white patches where the water hits it(never washed in machine). I have been trying everything to figure the cause(new washing machine, water softener, new soaps/no soaps, only cold water, ect, ect!) Now I am thinking it is the hot water heater leaving sediment on some of the laundry after it re-fills. Possibly chemically changing something in the water after heating or mixing with the softened water.????
Anyone hear of plain old well water(clear, no smell, no iron, little hardness) that fades cothes/anything it hits to white blotches? It doesn’t happen everytime, that’s why it has been difficult to diagonis. Also, we have a shared well but the neighbor has no water fading problems. I noticed that after showering when the hot water heater starts the water gets really really salty. No idea why?
Any advise welcome, half of my kids new school clothes are ruined AGAIN! UGHH!October 2, 2007 at 9:56 pm #7213Larry WeingartenParticipant
Hello Wisconsin: As you’re on a shared system, is someone adding bleach/chlorine to the water? Is there any odor? Possibly a water test is in order if nobody fesses up 😉
ps. Have your kids discovered the laundry bleach? Does the bottle seem to move by itself? Good troubleshooting makes no assumptions 😎October 2, 2007 at 10:08 pm #7214
This problem has presisted for for the past several years. The neighbor hasn’t cholorinated, no bleach in the house. You can literally see the water line on the shower rug and it hasn’t been in the laundry. What is even worse is I carpet cleaned (yes, stupid I wasn’t thinking about the water problems since it comes and goes). Well I used hot water and everything was fine for a while. Several weeks later I used a foam carpet spray and the carpet started turning white! No, it wasn’t the foam alone-I tested on a spare piece of carpet(repeatedly) no problems on the unwashed spare carpet. This was the final draw that started my mission to uncover this EXPENSIVE mystery water problem.
I have been testing and troubleshooting everything I can think of. I noticed some people discussing chemical changes with sediment after heating or softening on another site.
Any idea why the water gets overly salty after I hear the power vent running? You can feel it is really slippery from the salt. I saved a cup of it last night and in the morniing when I poured it out the bottom of the cup had a film from the salt. Does the pressure change and make more water sit in the softener? This could mean that sometimes sediment is pushed out and sometimes not causing periodical fading of materials.
Thanks for any advise.
Tammy from WisconsinOctober 3, 2007 at 10:56 pm #7218Larry WeingartenParticipant
Hello: Have you tried disconnecting/bypassing the softener? There clearly is a problem with it as very salty water should never make it to the taps. Imagine what it does to copper plumbing :shock:. I’m not expert in whether very salty water could have a bleaching effect, but if it did, your problem would be explained. Do the other locals soften their water? … The power vent water heater heating would cause a little thermal expansion, but that should not wind up putting salt in the water.
Yours, LarryOctober 4, 2007 at 4:56 pm #7223
Thank you for your response.
Yes, I have tried using non-soften water and by-passing the softener. We have had this problem for several years and just purchased a brand new softener(3wks ago) hoping to fix the problem with the fading/bleaching of clothes & bath mat. I think the problem with salty water after hot water tank re-fill is a setting on the new softener. I assume when I hear the power vent start it is because it just refilled and is heating the water. I believe it is unrelated to the fading problem because it is a new problem after the new softener was installed.
I purchased a brand new rug for the bath mat in front of the shower and noticed this morning that it has a faded spot about the size of a baseball on it. My new hypothsis is: something in the water is left behind after the water evaporates on the bath rug. This residue or deposit left behind could also make sense with the laundry problems. The patterns of fading after laundering are mostly tye dye looking areas. This pattern could be caused as the water is strained out of the material during the spin cycle.
Here are the problems.
1. Why does the problem come and go? Why isn’t everything in one load of laundry effected?
2. Who can I call to run tests to discover what is left on the material that causing this fading? (I called water testing facilities, they aren’t interested. They really aren’t scientists who uncover mysteries but rather “run of the mill” water testing services. They said “what test do you want run & here is the price”. It is up to me to figure out but I don’t know anything about chemistry to even advise a type of test!
I am still leaning toward something happening in the hot water heater. Maybe sediment that gets heated and changes composition? maybe it doesn’t always get flushed out into the water line which makes it more “potentant” to fade sometimes. Maybe even though I no longer use hot water for laundering some is left in the line??? I have no idea! I am so frustrated of trying to figure this out! I have so much other work to do and this is just one more problem!
Thank you for your advise. If anyone has any new hypothesis or ideas please pass them on. I am running out of ideas!
Tammy from Wisconsin
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