Intex Sand Filter Problem- i vacuum dead algea from pool floor & it keeps coming back

Hello-

I have an AGP 18x52 round Intex Ultra Frame Pool that came with a Krystal Clear Sand Filter Pump 14" model# SF15110. This is my second season of having this pool. At the end of the season last year some issues came up with what i thought was sand but it seems to be dirt and dead algea that was returning back into the pool and laying on the floor. I did everything according to the manual. I went over the "check-list" to see if I missed anything I should do as far as maintenance or chemicals.

My husband and I ended up doing the following:
1. replaced the laterals inside the tank (pool place told me this was the cause)
2. replaced the sand completely (pool place told me this was the cause) so we did this and the season ended and we closed the pool for the season.

Now this season my problem is getting algea out of pool and keeping it out. I have the appropriate chemical test kits to give TRUE number readings for CHL & PH and acid test, etc....my chems are spot on and water is CLEAR. Pump has great pressure, no leaks, but have been dealing with algea. I have done everything according to manual and idiot guides and still after shocking pool and maintaining great chemical numbers last night I had vacuumed to waste again to remove the dead algea from pool floor but after i was done cleaning the pool i turned it off and went to bed. Hubby turns on pool filter this morning and after 45 mins of pool filter being on, he tells me there is this stuff coming back in the pool still................I am ready to pull my hair out. Can you offer any suggestions to elliminate this for good? As of now, we have tank top off and I do see alot of debris on top of sand and thought I could perhaps remove and inch of sand and replace it with fresh new sand and try to see what happens. Is this a good idea or are we spinning our wheels??

Again, I use correct test kit for chemical stabilization and water is clear....what am i doing wrong??

------>Are the steps to properly remove algea from pool floor this: vac to waste?????
THANK YOU FOR YOUR HELP!!!!!!!

Cindy in DE

Hi, and welcome to the forum!

Can you specify what test kit you're using, and give us a set of test results (numbers, not "spot on" or "great") to look at? If you're having algae problems, then your chlorine levels are not being kept high enough (or perhaps you're not holding shock level long enough to kill it all off).

It's entirely possible that yuor pump is just oversized for your filter, and is driving the debris right through the sand. Does the problem change at all when the filter is backwashed? Is your pump pressure rising as the filter is running, and does it come back down after backwashing and rinsing?

We really need to see some actual water testing results to be able to better advise you. (NOT teststrips, though.) Make sure your CYA level is one of the levels you report. It may be the you are just not killing the algae although, it may be that plus a combination of your filter not working properly. Post some numbers and we'll go from there. Also, please put your pool's information in our pool chart.

Pool Chart Entry Form

Welcome to the Pool Forum!