Some of the things we love about the Seitz Supradisc II lenticular filters are that they are backflushable, hot water or steam sanitizable and storable. This means you can use them over and over again without the media warping; until they are full of solids or when a regeneration procedure doesn’t bring the differential pressure back down.

In this document we will discuss the best solutions for storing your modules correctly between uses to ensure longer use and higher throughput. They are always stored in a liquid solution and shouldn’t be allowed to dry out between uses. 

You can either store your modules inside the housing or find a suitable container with a lid where they can be weighed down to keep them fully submerged in the storage solution. For storage of longer than two days, we recommend removing the silicone gaskets or O-rings on the modules, otherwise they will become brittle and cracked and break up into little pieces. A brew fermentation bucket that is not tapered is suitable for the 12” modules whereas food grade plastic trashcans or Rubbermaid totes with lids are suitable for the 16” modules.

Here are a Few Solutions to Store your Modules in:

1. Cheap Vodka
If you choose to store your modules in vodka or your own produced spirits, make sure that it doesn’t exceed 135 degrees proof but it should be at least 40 degrees proof. Whenchoosing this method be aware that your module should be purged with gas before storage to ensure that little to no dilution of the alcohol takes place. If the alcohol % gets under 20%, you can get spoilage inside the module. Therefore, we only recommend using this method on 12” modules. 16” modules tend to take a lot more alcohol and we sometimes see poor distribution of the alcohol within the depth of the media which can cause spoilage.

2. Citric Acid with SO2
When choosing this method, it is a good idea to run this pickle through the modules before removing them into their respective storage containers to make sure you have even distribution. We recommend that the pH of the solution is pH 2.0 or lower and that you always maintain a 100 – 200ppm SO2 concentration. You may need to add more SO2 periodically. I like adding an effervescent SO2 tablet every now and then to make sure the SO2 level is high enough and that the citric acid solution hasn’t started to be spoiled by lactic acid bacteria. Take care not to breathe in the fumes. At such a low pH, the SO2 will be quite pungent.

3. Nitric Acid and Phosphoric Acid blends
Perhaps my favorite solution of storing modules, this method is typically used in the brewing industry where citric acid isn’t typically used and the absence of citric acid in your waste water is preferred. Nitric acid and phosphoric acid aren’t assimilable by microorganisms so you don’t need to add additional SO2. Food grade Nitric Acid/Phosphoric acid blends are widely used as sanitizers but also makes a great storage solution. Make sure that the solution contains no surfactants which may be tough to rinse out. You can make a pH of 3.5 solution and store your modules in this without having to add additional preservatives over time.

Whatever storage solution you choose, make sure that:

1. You regularly inspect the solution to make sure that your modules are properly submerged
2. All gaskets have been removed
3. That your solution is still sanitary or that someone didn’t replace the vodka with water to hide their vodka tonic habit...