pH , aeration, and a new heat pump

[VTPooler]

Hello all,

I had a new heat pump installed at the end of May. I've been keeping a solar cover on when not in use to try to keep the heat pump efficient. My pH seems to dropping pretty consistently to a 6.8 - 7.0 level not too long after I raise it, which I've done with both soda ash at times and baking soda at others.

My current readings are
FC 1.66
TC 2.24
pH 6.8
TA 109
CYA 29

I've been reading a lot about raising the pH by aeratinf, so giving a few tricks I found on here a try. Currently have a sump in the pool near the top trying to aerate. Also going to try to create (or buy) some type of makeshift PVC fountain that will screw into the return to bring the water our of the pool a bit.

I have a few questions:
-Trying to figure out why the pH keeps dropping. Would more use cause this, or maybe having the cover on a lot?
-If I get some kind of permanent (or even occasional) fountain type mechanism on my return, I think I'll need to try to balance usage of it with the efficiency of the heat pump. Is that assumption correct? Any tips on that?
-Would an inline aerator be a better approach to have less work around balancing with the efficiency of the heat pump?

Thanks,
Mike

 

[duraleigh]

How are you chlorinating? If you are using pucks, that is normally the primary reason your pH is dropping.

 

[Jimrahbe]

Mike,

My guess is that you are using chlorine tablets to chlorinate you pool.. They contain acid which lowers your pH. The more tablets you use the lower the pH drops.

I am not a great fan of tablets, but one thing you can do is to use a combination of tablets and liquid chlorine..

It also appears to me that your FC is way to low to prevent algae, so it is a good thing that you have a cover..

You should read this ... ABCs of Pool Water Chemistry

And check our our Pool School and see what the TFP pool care process is all about.. Pool School - Trouble Free Pool

Thanks,

Jim R.

 

[VTPooler]

Thanks Dave, Jim

My pool is 7200 gallons (12x20x4 above ground). For chlorination, I am using a combo of trichlor pucks in an inline chlorinator and liquid shock (10% sodium hypochlorite). I'd say probably about 50/50 usage between the 2, with using the trichlor more as CYA levels decrease. I have had the pucks for a few years (probably 3), since I bought a big bucket and don't use that many because I also use the liquid to maintain and the pool isn't very big. Do you think the age of them can be contributing?

Overall the pool has looked great for most of the season, even with the low pH. I have also noticed the FC getting used up pretty quick though also. I had some cloudiness last week when I wasn't able to be on top of the pool. Got the FC up to 5 on Saturday and the pH to 7.4 using sodium bicarbonate. It got rid of the cloudiness, but it did use up most of the FC in the process and today the pH is down to 6.8 again. There has been a little rain this week, but not too much, and the problem has been happening longer anyway, so the rain might be a factor, but probably not the primary factor. I am currently working to get the FC levels up to 4 again using the pucks, but it sounds like I should be doing that using the liquid instead.

Just looked up the pH of Trichlor (3) and Sodium hypochlorite (11), so I can definitely see why it would lower the pool pH. I think my plan will be as follows, let me know what you think.

- For now, use a combo of the liquid shock and aeration to get back up to 7.4 and FC of 4

- Be more conscious of the pH when choosing pucks vs liquid, but lean mostly towards the liquid ( or should I just stop using the pucks completely??..I still have a good amount left and just had the inline chlorinator put in, so I'd hate for that to have been a waste, but let me know your thoughts.

- Get some CYA separately so I don't need to rely on the pucks for it, but can use it from the pucks when needed


I'm still not sure I figured out an answer for aeration vs heat pump efficiency, but maybe it'll be a mostly moot point if the rest of this works out.
My wife thinks I'm crazy digging for answers when the pool has looked good outside of the few days I couldn't tend to it, but this pH has definitely been bugging me.