CH 550, fighting a small amount of algae

[Oceansol]

I haven't posted in a while, but I checked my signature and I think all the relevant info is there...

My pool has been great for years and has been easy to maintain. However, my CH is up to 550, and I'm pretty sure that it's because of the supply water mostly. I haven't refilled the pool in over 5 years, maybe more. Since I'm fighting some algae right now, and since I really have to clean my CG of calcium, I am thinking that it may be time to drain and refill. I can do an acid wash to clean up the calcium on the tile, and it will help keep the CG clean longer, I would think.

Is there a good or bad time of year to drain and refil? I am in San Diego but we won't be using the pool again until probably March or April.

If I drain, can someone recommend an acid wash process? I assume a diluted muratic acid wash....?

Also, I have my original Jandy paper-element pool filters. They are in good shape (visually) and I clean them regularly. How often should they be replaced?

Thank you

 

[mknauss]

Your CH is not that high. Entirely manageable. Once you get to 800+ it becomes more of a challenge.

You really should not have scale on your SWCG. Do you test your own water chemistry? What test kit do you have?

You should be monitoring CSI - Pool School - Calcium Saturation Index (CSI)). Do you?

I would not suggest acid washing your pool as it will degrade and damage your plaster.

The paper element cartridges should be fine as long as there are no tears in them and the plastic ends have not degraded.

 

[Oceansol]

Your CH is not that high. Entirely manageable. Once you get to 800+ it becomes more of a challenge.

You really should not have scale on your SWCG. Do you test your own water chemistry? What test kit do you have? No, I've been taking it to a pool store (I know, a no-no). But do know that I have always had scale on the SWCG. Sometimes more than other times.

You should be monitoring CSI - Pool School - Calcium Saturation Index (CSI)). Do you? I don't have all the values for calculating CSI, but I will try to get them.

I would not suggest acid washing your pool as it will degrade and damage your plaster So how do I remove scale besides not letting it form in the first place? I'd love to do so!

The paper element cartridges should be fine as long as there are no tears in them and the plastic ends have not degraded.

Good news there!

I'll get more thorough water testing done and report back. Pool math is pretty cool and very useful!

 

[mknauss]

Realize that pool store testing is notoriously wrong. In general, the forum is resistant to provide any kind of chemical guidance based on pool store tests. Invest the $100 and get a proper test kit. Get the Speedstir too.

It is very tough to get scale off your pool surface after it is formed. You can run a slightly aggressive CSI and it can help. You can do the acid wash you mentioned, but realize it will dramatically degrade your plaster.

I have had my SWCG for 4 years. I have far higher CH in my fill water and I do not drain/refill my pool until my CH reaches above 1000 ppm. I have never had to clean my SWCG of scale.

 

[Oceansol]

Understand about the pool stores. So if not high CH, what would cause the scale on the SWCG?

 

[ajw22]

Understand about the pool stores. So if not high CH, what would cause the scale on the SWCG?

Any combination of chemicals can give you a high CSI. Play with different values in PoolMath and you can get a feel for how the CSI varies. PH, CH, salt, TA, CYA, water temp, all affect CSI.

 

[Oceansol]

(For the record, I just ordered my TF-100 ) I'll post better numbers after i get the kit....

I have been using pool math to play around with different levels, so when I get more data I'll see how it all shakes out. I think I will run a test of my new kit vs pool store.

Incidentally, my supply levels for some of the key parameters are: (these are rough... I didn't factor in yet what percentages the 5 sources my city uses)
Total Dissolved Solids ~340
Total hardness ~140
calcium ~30
alkalinity 70
pH 8.2

I'm still not clear on why and how CSI levels affect scale, but hopefully even a numbskull like me can learn!