Clarifying DE backwashing process

[Idahoser]

Split from the DE Filter Cleaning Tutorial to keep the Sticky clean. jblizzle.

something about this I'd like to clarify:

On my pool at least, there's a pretty big difference in pressure depending on which valves are open from the pool into the pump.

When I'm charging the filter with DE, I have been setting the skimmer full open, all others closed. When I've finished charging and before moving the valves, I am at about 10 psi. When I open the spa and main drains halfway for normal operation, it goes up to 18 psi. This 18 is what I'm considering as the "starting pressure".

When I backwash, I open all of them all the way. Seems the max flow I can get is what I'm after in this case.

Am I doing it right?

 

[jblizzle]

Re: DE Filter Cleaning Tutorial

It does not matter what valves you have open as long as they are the same for the starting clean pressure and the what you use to decide if it is time to backwash.

Should be fine to open all the valves for backwashing. Although generally it is not common to have any suction coming from the spa all the time unless there is a way to be certain that you are always returning more to the spa than you are removing from it.

 

[Idahoser]

Re: DE Filter Cleaning Tutorial

...Although generally it is not common to have any suction coming from the spa all the time unless there is a way to be certain that you are always returning more to the spa than you are removing from it.

My pool and spa are connected together with a tube through the wall that allows them to equalize if I don't have the balance perfect, although it wouldn't be big enough if I was sucking down the spa hard. I have done that by accident before.

My return from the multiport valve goes out through the heater and then splits to spa/pool with a jandy valve, I typically leave that where the spa is closed about halfway and the pool completely open. The jets in the pool are much more forceful than the spa in this condition.

I have individual jandy valves on each of the inlets from spa, vacuum, skimmer, and main drain, then they join just before going into the pump.
For normal running, I didn't feel like it was a good idea to leave the spa with no circulation, so I have the suction from there and also the one from the main pool drain closed halfway, the vacuum closed completely (and there's a spring loaded cover on the pool end anyway), and the skimmer open completely.

For vacuuming I open the vacuum and close all the other inlets, and set the multiport to waste or filter, depending how bad it is. For running the Kreepy Krauly I use filter and I leave the skimmer inlet open halfway. For charging DE I open the skimmer and close the others. For backwashing I open all the inlets except vacuum.

Back when the heater worked, if we wanted to use the spa, we'd close all the pool inlets and outlets and have the spa full open. It would be nice to get that ability back but I don't know whether I'm really interested in a new heater, and the old one has had it I'm afraid. Winterizing that has been a bear, the drain bolts always strip. We replaced the iron manifold once already, then just gave up on it. I was seriously considering just cutting the pipes and installing a bypass so we wouldn't have to mess with it anymore. That's still tempting, and winter is coming.