My main pump and my booster pump went out on me; again. When I say the main pump went out, what was happening is the pump was having a hard time starting up and once it did it could only pull water if I isolated the suction side to the main drain. It also has been running very loud. Eventually it wouldn't even start. It used to pull OK from both skimmers and the main drain; however, I've always had trouble getting enough suction from the far skimmer even when I isolated the suction side to just the far skimmer. The booster pump went out earlier and I've been manually vacuuming for a while. It is completely seized. I took them to a local pump repair shop and the quoted repair cost is nearly the cost of completely new pumps. I have a couple of related questions so I'll pose them in order of priority. Note: I tried to include all the critical specs about my pool in my signature.
1. What size and type of main pump do I need? Can I get by with a single speed to save on the initial cost or should I get a 2 speed? I think I currently have a single speed motor. I've read several posts about pump sizing; however, I'm just not sure where to begin and I'm afraid I'll make the calculation more complicated than it needs to be. Background: I replaced both pumps once before since I moved in about 6 years ago. The first time I replaced my main pump was upon the recommnedation of my pool service (which I don't use anymore). This was relatively soon after I moved in before I knew anything about pools. The pool regularly gets innundated with leaves because of all the trees surrounding it and the skimmer and pump baskets were not the correct size so the impeller got clogged and the pump ran dry a long time. I paid a bundle for the replacement plus labor and I don't really know what I got (completely new pump or just a new motor plus some new wet side parts?) What I really don't get is why the pump says 1.0 HP but when I look up the pump model number (SP3010X15AZ) it comes up as a 1.5 HP A.O. Smith motor. So, I'm not sure if I have the right size for my needs. Based on the specs for my pool, do I need a 1 HP or a 1.5 HP? I still need to pick up my old pumps from the shop (I told them not to fix them) so I can't check what the SF is on the old pump until I get it back; however, that doesn't change my question. In addition to the specs in my signature, one additional spec that may be helpful is my electricity cost which is $0.0972/kWh.
2. What run time do I need? I realize the question/answer is based on my pump size (either my current pump or the new recommended config). Note: I'm trying to use a liquidator; however, it doesn't seem to deliver enough chlorine into the pool. Follow up question: With a 2 speed pump does the amount of chlorine delivered from the liquidator per turnover stay the same regardless of the flow rate? (i.e. if I run a 2 speed pump longer on a lower speed or a single speed pump a shorter amount of time to get the same turnover will the same amount of chlorine be delivered from my liquidator?) Second follow up question: If the liquidator cannot deliver enough chlorine for my size pool is the answer to add another liquidator to the system; and, if so, in series or in parallel? (I realize this isn't a pump question so I can move this to another thread if needed.)
I think I'll stop there for now and see what recommendations y'all may have. When I get my pumps back and I have a clear diagnosis of what the problems are I'm going to post additional questions with more information and ask for help to determine why I'm having problems with my pumps and what I can do to remedy the situation.