Pool Filter Comparison and Strategy

3rd summer with our pool. Learning as I go... Hence the name.

Multiple questions, and looking for suggestions/opinions on issue below.

I currently have a cartridge filter system. This spring I opened the pool to thick green algae. The pool service I use told me to clean the filters 1-2x daily until the water was clear. I've done this by hosing filters thoroughly, and soaking in bleach water. but it has been getting worse.
Q1) Is there a better way to wash filters? should I let them dry before retuning to the system?

After much frustration and little progress, (Shocking with heavy chlorine has helped, but water stil not moving through filters.) and sending the filters to my pool servicer for a deep clean, they contacted me and "Strongly" encouraged me to swith to a sand filter system. I am hestitent to do this because of the cost, but also because my cartridge system is 2 years old and it seems that the jusry is still out on which is better. Sand or Cart. I know they are partial to this system, but being a novice, it is hard to know which way to go. especially looking at this added investment.

Q2) Should I make the investment ($1300 installed), and go Sand? or should i fight through the rough patch of initial cleaning (system has worked well past 2 yrs when heavy Algae was not present from warm spring.)

Q3) I have also seen a bit of talk around "doubling up"Sand filter feeding into a Cart. filter for the best of both worlds. Is this adviseable? Can it Be done? Cost should be the same as I already have the Cart. Filter syst.

Any input is greatly appreciated... And I hope Ben lets me out of Pool Forum Purgatory so I can learn and participate more in this area.

1. Your cartridges may be toast, or they may have been low grade to begin with, or . . . several other things. Post your EXACT pump / filter make / model PLUS your OTHER pool info (gallons, surface type, other equip: heater, SWCG, feeder, etc.)

Operate with the cartridges removed, and see if you have adequate circulation. Read the test kit page; get a local OTO or HTH 6-way; order a K-2006; test tonight with what you can find locally, and tell us the results. Tell us what the pool looks like and, if possible, send a picture to poolforum@gmail.com

2. Filters in general, do not do well with live algae. It sounds like you still have live algae: kill it! Is there thick sludge on the bottom? Are you on a tight budget, or is getting the pool cleaned up quickly a higher priority? (Best way to kill it depends on in asked for in #1 PLUS your priorities.)

3. Doubling up filters is NOT a good idea.

4. Most of the people who can give you accurate and reliable info -- the moderators and the PF Support Team -- can see your post right where it is, right now!

Personally, I would not be in a big hurry to change from cart to sand UNLESS the cart filter you have is undersized for your pool or being overdriven by too large a pump (which would be better served by changing out the pump!). Follows the advice in PoolDoc's post above and once we see what you have we can better help you come to a decision.

I can't imagine how it could cost $1300 to have a sand filter installed!

What is a reasonable cost for this type of filter, installed?

That's going to vary by region, but around here, the filters run around $500, and installation is $75/hr plus a $95 service call. Shouldn't take more than a couple of hours, plus the cost of the sand. I would think $1300 is excessive.