I have a 40 year old concrete pool with fiberglass panel walls. I have separate skimmer and main drain lines. The pool is surrounded by a concrete apron and there is also a brick patio (with concrete underlayment) in between the pool and the equipment room. I believe the main drain line is black ABS.
I've owned the house for 5 years. The first 3 summers, the main drain worked great. Towards the end of last season, there appeared to be a small leak that developed somewhere in the main drain line. I closed the pool as I normally would last fall. This spring we had some torrential rains before I opened the pool (I have a mesh cover). Despite the heavy rains, when I took the cover off a couple weeks later, the water level was low--essentially right below the skimmer. This season, I have only used the skimmer line but have tried out the main drain line a couple of times. Yesterday I blew the line out from the pump side with an air compressor to be sure there was not an obstruction in the line. Water pushed through easily and was bubbling strongly up from the drain. After confirming no obstruction, I turned the pump on, shut the skimmer line valve and left the main drain valve open. I can see water in the pump moving up and down and occasionally looks like it might go "whoosh" but never does. The instant I open the skimmer line, I get full suction pressure. So, the apparent leak is significant enough to prevent the pump from maintaining suction when I have the skimmer line shut off and rely solely on the main drain. But it's not significant enough to cause an issue when I have both lines open. But I've kept the main line closed all season, relying solely on the skimmer line, which has been fine. But I want to figure out a plan for the main drain.
I have a couple of questions and am looking for some input on my options. As I see it, they are:
1) continue doing what i'm doing - filling up the pool a couple of times a week to make up for the lost water, leave the main line open but don't use it;
-Does the fact that I am continuing to lose water despite not pumping any water through the main drain line indicate that the leak is somewhere deep, close to the drain itself? If the leak is
up closer to the surface, I shouldn't be losing water if I'm not pumping water through that line, right? If the leak is low, I would have expected the water level to be much lower in the spring
after a whole winter of losing water.
-Will I be able to keep water out of the main drain line when I close the pool? Doesn't a leak prevent me from achieving an air lock? Will the problem just get worse? Does the fact that it's
ABS pipe make any difference?
2) eliminate use of my main line altogether by installing a plate over the drain;
-If I eliminate the main drain, do I need to do something to get the water out of the line? Will a shop vac from the pump area do it?
-Assuming I am able to get the water out, do I need to do anything with the main drain line when I close or open the pool in the future?
3) contact a leak detection service to try and identify the area of the leak and repair it - or hire someone to repair it;
-I'm assuming that the leak is going to be somewhere under brick and concrete, and so the repair will cost at least $3-5k. Is it worth it to have a main drain when my skimmer works perfectly
well?
4) try installing some type of liner with a bladder.
-Has anyone had good or bad experiences with these? Does the fact that my line is ABS pipe with connectors make a difference?
I know that's a lot of questions but really any input on any of these topics is greatly appreciated as I consider my options.
Thanks in advance.
I've owned the house for 5 years. The first 3 summers, the main drain worked great. Towards the end of last season, there appeared to be a small leak that developed somewhere in the main drain line. I closed the pool as I normally would last fall. This spring we had some torrential rains before I opened the pool (I have a mesh cover). Despite the heavy rains, when I took the cover off a couple weeks later, the water level was low--essentially right below the skimmer. This season, I have only used the skimmer line but have tried out the main drain line a couple of times. Yesterday I blew the line out from the pump side with an air compressor to be sure there was not an obstruction in the line. Water pushed through easily and was bubbling strongly up from the drain. After confirming no obstruction, I turned the pump on, shut the skimmer line valve and left the main drain valve open. I can see water in the pump moving up and down and occasionally looks like it might go "whoosh" but never does. The instant I open the skimmer line, I get full suction pressure. So, the apparent leak is significant enough to prevent the pump from maintaining suction when I have the skimmer line shut off and rely solely on the main drain. But it's not significant enough to cause an issue when I have both lines open. But I've kept the main line closed all season, relying solely on the skimmer line, which has been fine. But I want to figure out a plan for the main drain.
I have a couple of questions and am looking for some input on my options. As I see it, they are:
1) continue doing what i'm doing - filling up the pool a couple of times a week to make up for the lost water, leave the main line open but don't use it;
-Does the fact that I am continuing to lose water despite not pumping any water through the main drain line indicate that the leak is somewhere deep, close to the drain itself? If the leak is
up closer to the surface, I shouldn't be losing water if I'm not pumping water through that line, right? If the leak is low, I would have expected the water level to be much lower in the spring
after a whole winter of losing water.
-Will I be able to keep water out of the main drain line when I close the pool? Doesn't a leak prevent me from achieving an air lock? Will the problem just get worse? Does the fact that it's
ABS pipe make any difference?
2) eliminate use of my main line altogether by installing a plate over the drain;
-If I eliminate the main drain, do I need to do something to get the water out of the line? Will a shop vac from the pump area do it?
-Assuming I am able to get the water out, do I need to do anything with the main drain line when I close or open the pool in the future?
3) contact a leak detection service to try and identify the area of the leak and repair it - or hire someone to repair it;
-I'm assuming that the leak is going to be somewhere under brick and concrete, and so the repair will cost at least $3-5k. Is it worth it to have a main drain when my skimmer works perfectly
well?
4) try installing some type of liner with a bladder.
-Has anyone had good or bad experiences with these? Does the fact that my line is ABS pipe with connectors make a difference?
I know that's a lot of questions but really any input on any of these topics is greatly appreciated as I consider my options.
Thanks in advance.
