Using flock also

[Kellyo56]

Moderator comment: This post was separated out from this thread: Using flock


I read this thread too late. Pool store sold me 2 bags of aluminum sulfate to put in my brand new pool due to high phosphates. I added last night , had filter off. Just vacuumed to waste the first round of stuff off the bottom. My question is while I wait for more to fall to the bottom do I have my filter running or add any shock? I have a sand filter. Thank you.

 

[Texas Splash]

Hey Kelly and welcome! At this point, with what would appear to be more floc still suspended in the water, I would let it fall and vacuum to waste again. You do NOT want that stuff in your sand or you could very-well have to change it after. Not good. Once you've vacuumed to waste as best as you can, then you can go back to filter, chlorinate with bleach or whatever product you use, and adjust the other levels as necessary.

Since you are new though, I would recommend you review the TFP ABCs of Pool Water Chemistry page, and also save the Vital Links below in my signature. They, along with the proper test kit (TF-100 or Taylor K-2006C) are the foundation of what we do here at TFP.

 

[Kellyo56]

Thank you so much! My pool was clear and beautiful but couldn't keep the chlorine up. Now it looks like milk :/.

 

[RobertScalchi]

I have a question Texas Splash about flocculant used. I haven't used the stuff to clear a pool in 2 years as I've implemented other strategies to filter out fine debris to clear a pool.

I understand the adverse affects flocculant has on Sand and DE filters, but how does is specifically and adversely affect cartridge filters that cannot be bypassed unless removed, and vaccum to waste utilizing the drain port? I was just curious how the aluminium sulfate affects the pleats fibers?

 

[Texas Splash]

but how does is specifically and adversely affect cartridge filters that cannot be bypassed unless removed, and vaccum to waste utilizing the drain port? I was just curious how the aluminium sulfate affects the pleats fibers?

Robert, I can't speak too much for the chemical properties portion of your question, but for the most part, pools with cartridge filters don't have a method to pump to waste. Just one of the downfalls of that set-up unless a user plumbed one in after-the-fact or specifically requested such a method from the builder at construction. So just like the sand and DE, once the floc embeds in the fabric of the cartridge, it's very difficult to remove. One could try a TSP soaking, but there's no guarantee it will work since it's just a soaking and there is no agitation or scrubbing between the pleats and other areas.

 

[RobertScalchi]

Thanks Texas Splash. I guess what I am asking the answer to, is what happens when the flocculant embeds in a cartridge filter pleats? How does it make the fibers and filtration less effective? What would be the scenario and result if it did? I know it clogs DE and sand.

When I vac to waste it still doesn't technically bypass the filter but the water does go to waste. I install the shut-off valve at the drain port.

 

[Texas Splash]

My C1200 has a similar set-up with a spigot at the bottom. But as you noted, it's not a true "vacuum to waste" set-up. With the other filters that have a MPV, the water never touches the inside of the filter. When we pull water into a cartridge set-up and let it go out that spigot, the water is still circulating within the housing, so any product (i.e. floc) is still touching everything inside. Floc has a tendency to gum-up products in a filter, leaving a residue and coating that is not always easy or practical to remove. With our pleated/paper filters, once those get coated, they lose much of their filtering capability. Water simply can't pass through as effectively. In some ways, you could compare that scenario to someone who does an acid wash on a paper filter before cleaning it thoroughly. The acid will actually bond the residue to the cartridge and it then becomes useless. I understand the water travels trough the middle and around the cartridge as well, but those pleats and paper elements are still required to breathe to some degree.