Lately, after vacuuming my in ground pool with my manual vac I've noticed the dirt coming right back and settling on the bottom within minutes. The vac has good suction. I'm thinking the vacuum or the cartridge filter is somehow not working. We clean the filter once a week which is probably much higher than normal. There is nothing visibly wrong with the filter cartridge. I have these small black particles ( dirt, tree droppings? ) that end up on the pool floor. I recently had some branches trimmed that were near the pool but one was too big to cut. I do have a screened pool cage over the pool. I need to vacuum at least once a day if not more and I'm really getting tired of that. Kinda takes all the pleasure out of the pool. Any ideas? Thanks !
Strange Problem
- Thread starter Dave2590
- Start date
- May 3, 2014
- 58,834
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Sounds like dead algae. What are your water chemistry results? Do an Overnight Chlorine Loss Test.
Thanks for your reply. My water chemistry is fine. Pretty sure what I'm seeing on the bottom of my pool is not dead algae based on pictures I've seen. I have tiny black particles that appear to be related to the trees around and over my pool. The particles are small enough to drop through the pool cage screening. My thinking now is that the particles are going right through my cartridge filter and back into the pool after vacuuming. However my filter looks fine to the naked eye and the water is very clear. The filter came along with the house when I bought it 3 years ago. Its a very old aluminum filter made by Tropic Flo-Harmsco ( Model # F-150 ). There is no pressure gauge on top. I did find a replacement cartridge but had to look high and low. Should I buy a new cartridge? Soak the old one? Thanks !
A typical cartridge filter will filter anywhere between 5-20 microns. 20 microns is about the size of a white blood cell and not visible to the naked eye. Unless your filter is compromised in some obvious way, these particles are probably not returning to the pool through your filter. To convince yourself of that, tie a nylon sock over the closest return to where you are finding the particles and then vacuum again. If the sock fills up with the particles, then you should replace your cartridge. If not, you should post a full set of test results and perform an OCLT like @mknauss suggested.
Thats good advice. I decided to check the cartridge again. Lo and behold I discovered that pieces of rubber had broken off the bottom seal. I followed some advice to look down the middle of the cartridge and thats how I spotted it. Like most other people I always stand the filter upright when I clean it and never thought to check the bottom. We did put a sock over a return and we did get debris but it was hard to tell because water pressure pushed the sock off. New cartridge on order ! Thank you.