Lapierre Soap Foaming

[Amber Gold]

Every year now, I've used Lapierre's soap to wash membranes and it's always foamed a lot during the wash cycle. Before this year, I had a big wash tank on the Lapierre 250 that was only partly filled, so it wasn't a big deal. This year, I have a Turbo Compaq with a narrow wash tank that needs to be filled all the way, so it was always foaming over...makes a mess. I asked various Lapierre rep's at their open house and none of them have experianced this problem and had no suggestions. I have tried dumping the wash water in at the top of the tank and at the very bottom and it still foams just as much. Aside from it making a mess, it also makes taking pH readings harder. Is anyone else having the same problem? I think Lapierre's wash soap is straight sodiium hydroxide.

I'm almost out of this tub of wash soap, so I want to stock up on something else for next season and not have the same problem.

Thanks

[Amber Gold]

Never got any responses last spring, so giving it a bump. Thanks

[sapman]

I use the powder Leader sells. I sometimes have foam, and my understanding was that the membrane was probably pretty dirty those times. So I think I usually do a second washing after a partial rinse when that happens.

[Maplewalnut]

I also use lapierre and do have some foaming. I assume like sapman it's when it's pretty dirty. I also have a greenish tint to the water from time to time when I switch it to rinse the next morning

[Thad Blaisdell]

I will tell you what I do. First is to rinse to get all the sugar out. Next is to get the water caught and put in the soap, I don't get to worried about the ph at this time (I don't go crazy with the soap either). I then start the wash and I use the High Pressure Pump and let it run for 15 min or so. I then drain and rinse. The water is always brackish, green tint and nasty. Then I start over doing the wash cycle. Turn it on and let it go till finished. Since I have started doing this my membranes have always stayed better longer.

This may help in this situation as well. Now my only question is this, does the water returning to the catch basin splash in the water at all or does it cycle into the bottom of the basin? Also do you run the HP pump?

[dabamvt]

Josh,

Our first time washing last year was a soap bubble nightmare! We had used the right amount of soap and correct amount of water. We had bubbles everywhere. The return line was just above the water level and was constantly agitating the water and creating all the bubbles. We extended it down to about 3" from the bottom of the tank and have not had anymore issues. We have a Lapierre RO and used their soap.

Dale

[Amber Gold]

Thanks for the responses.

When I'm done for the night, I rinse the sugar out, rinse to drain for say 10 min. to get the crud out, then wash cycle w/ soap, then final rinse to drain. I get the foaming every time. I always had a foaming problem with the 250, but with the bigger tank, only filled 1/3 of the way, so it didn't make a mess. The new tank is taller, narrower, filled all the way and makes a mess.

I tried having the pipe discharge above the water and well into it and it still foams. I could bringing it to the bottom of the tank, to see if that helps, but then aren't you short circuiting the wash tank? Sending the discharge right near the tank's outlet to the feed pump?

With the Turbo Compaq, there is no recirc. pump, so the HP pump runs w/ the feed pump. On the Lapierre, only the feed and recirc. pumps ran.

Foaming happens every time, early season and late season, so not sure as it's tied to how fouled the membrane is. I will be getting a new membrane for this season, so maybe it'll help??

When adding soap, I start with say 1/2 of a sample cup size, then go back 20 min. later to check the pH and add more.