Upgrading from cartridge to sand filter

[kython89]

I thought I replied to this but I'm not seeing it. The OCLT was < 1. The CC is 0. I got the stabilizer up to 50 and the chlorine level is holding at the SLAM target.

I've been running the robot a few times a day.

The pool is getting clearer and clearer by the day.

After reading the wiki for cartridge filter care and looking back and Amazon orders I realized my filters were going on 4 years. I initially thought this was year 2. I guess time flies. At any rate I ordered a new set and they are staying cleaner for much longer. I also got an Aqua Comb and some filter cleaner. I was just hosing them off with a bronze nozzle.

To vacuum the pool through the filter fills the cartridges up pretty quick so I'm avoiding that. Any time there is a large wind storm the pool is a mess because given the T shape we don't have a cover other than the winter cover.

You can also install a cyclone prefilter that is supposed to capture debris before the filter. It’s more of a gadget we don’t recommend but may solve your pool opening problem.

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Why don't you recommend these gadgets? To your point it kinda seems like the right solution to my problem aside from a back washable sand filter. It keeps the superior cartridge filters in place but allows a good solution for vacuuming after severe weather event when the robot gets overwhelmed.

+1 on the algae test.

Food for thought; what if you simply installed a 3-way between your pump and filter and vacuumed to waste at the start of the season? Ideally none of that junk goes through any filter.

I'd invest in that $80 valve and a new VSP instead of a sand filter if it was me. Assuming the pool is well behaved the rest of the year.

How does this compare to the pre filter solution? It feels like vacuuming to waste would result in substantial drop in water level.

 

[Bill1974]

If you have room to add a sand filter, I would add one (plumb it in parallel and not series) using a couple of 3 way valves in so you can choose which filter to use. This would also give you the option to filter to waste. Kind of the best of both worlds. Once the initial opening is cleared up switch to filtering with the cartridge filter.

 

[Flying Tivo]

If water cost is not an issue i would go for the largest Sand Filter available or that would fit your pad. Have you used Skimmers - Further Reading

 

[bradgray]

How does this compare to the pre filter solution? It feels like vacuuming to waste would result in substantial drop in water level.

We can't compare them - they aren't at all the same approach to a solution. One removes the material entirely from the pool, the other is another attempt to filter it.

The centrifugal pre-filters will only remove heavy particulate like granular sand. If you have finer silt and other light debris, it won't do you any good. They provide some benefit in my area, but our county is red sandstone and our primary contaminant other than guests is unadulterated sand.

As far as water loss, that was addressed in my recommendation to trade your dollars for the VS pump you referenced in your first post. If you vacuum to waste with a variable speed, you can choose the lowest flow that will capture the debris and you will lose very little water. Throw a fill hose in while you vacuum if you want to mitigate it in real time. I also think you underestimate how much water it takes to backwash a sand filter - and you will be backwashing a lot. Sand filters clog far more quickly with far less than a cartridge system does.

Direct removal of the contaminants from the pool is far and away the best solution based on your photos. There is no need to burden the system with a worst-case clean-up every year if you can prepare and prevent it. Your water replacement cost will be negligible and certainly less than the chemicals, carts and your time cost you trying to fix the system that was just bludgeoned with pounds and pounds of debris.