How Do I Keep My Pop up Pool Water Clean??

Well I have an inground pool that's pretty large so this advice may not apply to you, but for me, weekly maintenance includes algaecide as well as shock. Algae is what kills your chlorine levels so if you don't keep that in check, you can find that your chlorine levels will plummet and are very hard to get back up. Generally once you get the pool stabilized, you just need to test the water daily and tweak things here or there, like you're doing, and keep up the weekly treatments, which include shock and, at least in my case, algaecide. Vacuum and skim debris regularly as well as dirt, leaves, and insects can mess with your chemical balance.

Don't use the testing strips. I was using them and they kept showing the pool had no chlorine so I kept adding more. I used the kit with the red and yellow bottles and the chlorine was REALLY high. Our pool has about 5000 gallons. I put 1/4 cup (2 oz.) algaecide in every 3 days. I have the plastic floating chlorine holder and fill it with 1 oz. Chlorine tabs every other day. I add baking soda when the ph level is off. They sell huge bags for this purpose at Walmart near the pool supplies. We run the filter system early in the morning and late in the afternoon for 3 hrs. each time. Hubby set up a timer so it comes on automatically. I rinse the filter out every 2 or 3 day and relace it after 2 weeks, sometimes sooner. I shock it once a week.

The biggest culprit in bringing your chlorine levels down is....the sun.

So if you want to keep your levels stable, you need to put a cover on your pool. A dark lined one. That will help keep the levels stable much longer.

For algaecide: When you notice algae. First, shock your pool. When the chlorine levels come down to normal, add your algaecide that night. Vacuum out the dead algae the next morning. Adjust Ph as needed.

We have the 18ft metal frame intex pool. The BEST thing we ever did was buy a sand filter and the salt water system. We started with the regular chlorine but were never able to get the balance right. In the long run the salt water system is cheaper. 1 bag of $6.00 pool salt lasts about 4 months. Once the salt water system is going you never have to add anything the system takes care of it. I'm in South Florida so we keep our pool up permanently and it is always crystal clear. We don't use a cover at all so the only maintenance we have to do is vacuuming the bottom and cleaning the sides as needed.

Stabilizer and algeacide. Small pools are hard to balance.

I don't have any answers for you. As we often struggle too. The only thing that works for us is to run our filter longer! Like 8 hours a day!
I do disagree with putting the cover on. For us, putting the cover on heats the water up and keeps the heat in. Warmer water means the chemicals burn off faster and algae grows quicker. Once it starts getting warm, we never cover it up.