Aerating Pool to raise PH - Hiblow XP40

[novice321]

Hi all,

Firstly, to get to the point:

1. I removed the L tube that came with my aerator and directly connected the tube I bought to the outlet port. This should be ok right?
2. How do I keep the tube underneath the water when the aerator is on?
3. Is an air stone necessary? All of the air stones I have seen online have such a small outlet to connect to. My fear is if I attached a 16mm tube onto a 4mm tube through the use of reducers would that not adversely affect the longevity of the pump?
4. Is the efficacy of the bubbles affected by how deep or how close to the surface I keep the tube?
5. After turning the pump on, do you think I should be testing PH after every hour/2 hours/3 hours...?? (PH very low atm and TA is OK)

Now the longer version

So I have a small inground pool which holds just over 15000 litres of water (15300l approx). Like many in the UK, I seem to be having the problem of very very low PH and "OK" alkalinity: If I use PH plus to balance it, the TA goes too high. Then I lower TA, only for the PH to go down again and repeat. SO through the power of the internet, I learnt that by aerating the water I can raise the PH without raising the TA (although I don't fully quite understand if its the bubbles that raise the PH or the addition of Oxygen: oxygenation). Thus I bought the Hiblow XP40, which is used here for aerating ponds of up to 15000 litres. Although little did I know that it doesn't come with any air line / tubes. So I got in touch it Hiblow who said "The pump comes with a 5/8” ID L tube that fits over the outlet port. You can use a 5/8” OD barb to fit into the L tube and then adapt it to whatever size tubing you need.

I then phoned them and the technical department guy informed me I need a 16mm ID tube (which is about 21/22mm OD). Having visited 4 stores, I figured Amazon it is. Today the tube came.

But guess what? The tube is exactly the same diameter as the L tube shown above. So instead of going through the trouble of using reducers etc...I simply removed the above L tube and directly connected the tube I bought to the outlet port. This should be ok right?

Next I inserted the tube in the pool and turned on the pump but the air tube keeps rising out of the water (surprise surprise). So I used a cable tie and loosely attached the hose onto the pole of the pool brush then lowered the brush into the pool. Now the tube stays underneath the water and I finally have some bubbles. I know this is a dodgy DIY solution but how would I properly ensure the tube stays inside the water?

Also is an air stone necessary? All of the air stones I have seen online have such a small outlet to connect to. My fear is if I attached a 16mm tube onto a 4mm tube through the use of reducers would that not adversely affect the longevity of the pump?

Also is the efficacy of the bubbles affected by how deep or how close to the surface I keep the tube?

I know no one can tell me exactly how long it will take for the PH to rise up to normal levels but the current PH is VERY orange (Orange = very low PH, Red = too high PH). The TA level at the moment is on the higher end of "OK". Do you think I should be testing PH after every hour/2 hours/3 hours...??

Any help would be most welcome.

Thank you

[Teapot1]

It sounds like you have it setup correctly, I have used a vinyl dumbell weight in the passed to keep things weighted down. Sounds like you are using test strips (dip strips) despite getting some sort of colour change that won't relate to the printed ink colour on the packet, dip strips are notoriously innacurate, a guess at best and could send you in the wrong direction at worst, please do yourself a favour and buy a decent test kit.
How deep, deeper the better, fine bubbles are better than great big large ones. How quickly you get a change in pH depends on how high the TA is. As you lower TA you need to aerate for longer as there is less disolved carbonates to be released. To start with I would measure 4-6 hours then lower the pH if it has increased to high 7's. I run my pool between 40-50ppm TA and only added acid this year for the 1st time in 3 years. Will be aerating again in a few weeks.

[Phil.c]

After topping up my pool by about four inches I notice that the PH is 7.2 but the ALK it way over 200, so I'm adding quite a lot of PH lowerer to get it down to the correct level, Teapot has a pictures of adapting a submersible pump, my pump is different as there doesn't seem to be an area to drill a hole for the air intake, so on the weekend I'm going to try a different method.

From the water input underneath the pump, I'm going to attach a hose, so the pump, hopefully will not only drag in water but also air from the hose which the other end will be above water....we shall see?

[Denniswiseman]

I use https://www.amazon.co.uk/Velda-125099-6000-Silenta-Pump/dp/B00388KBIW
4https://www.discountleisureproducts.co.uk/aquarium-supplies-c3/aquarium-air-pumps-and-accessories-c29/kockney-koi-yamitsu-giant-can-pond-and-aquarium-air-stone-p520
2 tee to connect 2 air stones together and 1 tee to separate the lines going into the pool
Using 4/6mm tubing
The air stones hold the tube down
I've never had a problem and get a good air supply

[Phil.c]

Thanks, if you method doesn't work I'll go for your suggestion.

[Phil.c]

Just realised that my pump output is 2" so going to buy the 6000.

[Phil.c]

The aerator has arrived but I'm still lowering the PH to lower Alk, lots of chemicals going in and now the Alk is down to 220!

Once the Alk is down to the right amount, roughly how long does it take to raise the PH with the 6000 aerator? I know that the higher the Alk the faster the PH will raise so what is the recommended amount of Alk before using the aerator please?

[Denniswiseman]

Can't say just run it for a day and check
Did you get 4 airstones so you can spread the air about more
You can run it while lowering your alkalinity

[Phil.c]

No, I forgot the extra two, but will see how it goes

[Teapot1]

Once the Alk is down to the right amount, roughly how long does it take to raise the PH with the 6000 aerator?

What is your right amount? Kine is 40-50ppm

[Phil.c]

Once the Alk is down to the right amount, roughly how long does it take to raise the PH with the 6000 aerator?

What is your right amount? Kine is 40-50ppm

A lot less than 220

I read, between 80 and 120ppm the higher the better to keep PH stable?

[Teapot1]

Haha thats about where I started from, incredibly high in my area surprised it isnt fizzy

[Teapot1]

I read, between 80 and 120ppm the higher the better to keep PH stable?

Thats industry BS and is only related to concrete and tiled pools where the plaster/grout needs it.
My pH is stable and been so for 3 years, at 40-50 ppm there is still 7-8 times more dissolve CO2 than in the air above. Industry guidelines many many more time so it off gasses quicker raising the pH sooner. The CYA in your pool also acts as a buffer but in the opposite direction lowering pH so between the 2 at 40-50ppm its rock solid pH wise. That said if your pH is stable at 7.8-8 it really doesnt matter and does not effect the chlorine sanitiser as much as the CYA does so it can for the most part be ignored.

[Phil.c]

Thanks, interesting

[Phil.c]

My ALK is now down to 54 and PH 6.8, aeration on, so a check later today to see the increase.