Mustard algae on the sides and 2-3 green algae spots.

[totalnoob]

Hi!

I have been successfully managing my pool for last 5-6 years using knowledge gained here. and I was at the point where I could eye-ball my pool and judge if I need to add chemicals and approximately how much. Well things happened with life, and I kind of couldn't focus much on the pool. I will still dump chlorine and acid, and this was pretty much it. Now, this summer, pool started giving trouble, and I thought ok, I need to start working on the pool and take care if the issue. So, basically, at this point, I have mustard algae at couple of spots on sides of the pool, and couple of green roundish spots. Mustard algae, I brush off and then it comes back after some time. Green spots, are sticky and can't be brushed of.

I tested water for pH and chlorine levels, pH is 8.0 and FC is 4.5 ppm, CC is 0. Did overnight test, and FC was still 4.5 ppm, and no CC.

Took water to Leslies, as I was out of cyanic acid, so I thought of getting their results too.
CH: 180
CYA: 30
Total Alkalinity: 120
Total Dissolved Solids: 4200. This is high, and I don't know how it came to this level as I have been using liquid chlorine for over 5 years now. Could it come from Costco pool shock (see below please).

I recently added 2-bags of Costco pool shock (as there was lot of algae growth, and it did help). 2nd bag was added about 7-10 days after the first one.

Advice please on what should I do to get rid of this sticky mustard algae and the green algae?

Couple more questions:

Liquid Chlorine: freshness matters? I generally buy about 10-12 bottles from Lowes, and leave them in garage. Some bottles might be sitting in garage for 8-12 months as I keep buying new bottles and then use the new ones first.

Costco: pool shock. Is it a good idea to use it instead of liquid chlorine to increase chlorine levels? It is convenient to use, just dump one bag and be done for some time as I think due to it being a shock, it raises chlorine level to shock levels.

TIA for your help.

 

[mknauss]

So, as you know, pool store tests are not relied upon.

So think about it, if your TDS is 4200, and your CH is low, CYA is low, the only real thing left is salt. You have nearly 4000ppm salinity? I struggle with their numbers.

The Costco shock is cal hypo with copper algaecide. Do not use it. Use liquid chlorine. The green patches that won't come off, that is not likely to be algae. Could be the start of copper staining.

Liquid chlorine in your garage is saltwater in a couple months during summer. Freshness matters a lot. Lowes and Home Depot store the LC outside. It gets warm in Folsom. So be aware of that.

You need to SLAM to rid your pool of algae if, as you say, you have mustard algae. Try some vitamin c on the green patches. If they darken, they are copper.

 

[jseyfert3]

Edit: Oops, made a mistake. Disregard.

 

[totalnoob]

So, as you know, pool store tests are not relied upon.

So think about it, if your TDS is 4200, and your CH is low, CYA is low, the only real thing left is salt. You have nearly 4000ppm salinity? I struggle with their numbers.

The Costco shock is cal hypo with copper algaecide. Do not use it. Use liquid chlorine. The green patches that won't come off, that is not likely to be algae. Could be the start of copper staining.

Liquid chlorine in your garage is saltwater in a couple months during summer. Freshness matters a lot. Lowes and Home Depot store the LC outside. It gets warm in Folsom. So be aware of that.

You need to SLAM to rid your pool of algae if, as you say, you have mustard algae. Try some vitamin c on the green patches. If they darken, they are copper.

Thanks for the reply, and the advice. I know pool store tests are not to be relied upon, but I wanted to get an idea. Anyhow, I think its time for me to get serious and start testing water myself. I was shocked when Leslie's said that I have very high TDS and tech was like are you sure you don't have salt water pool, and I was like Yup, I am sure of that part at least

I kind of guessed that liquid chlorine freshness might matter, and that's what you have confirmed. So, where do you all get your liquid chlorine that is fresh and is not stored outside?
And, where to store it once it is picked from store (that doesn't store it outside).

Where is copper staining coming from? I don't add any copper to my pool (well at least before adding the Costco shock).

Why is it not a good idea to use Costco shock? Genuine question, want to learn. My Costco goes through it like crazy, so must be working for people, but then all those folks probably don't come here

Yeah, Folsom does get hot, we had almost 20 100+ days in July & August.

 

[mknauss]

You can use Cal Hypo if you want for chlorine additions, just realize it adds calcium. Your testing shows you have low calcium, lower than you should if you have a gunite pool. Your fill water must be low in CH. Just do not use the cal hypo that has other additives, like the Clorox stuff Costco sells.

TFPC never 'shocks'. We SLAM if necessary and then maintain FC in a target range based on CYA.

- - - Updated - - -

Store your bleach inside. Laundry room?

Check pool stores and Walmart for liquid chlorine. They typically store it inside.

 

[arri]

Just a quick follow up on chlorine freshness in the big box stores. For those who aren't already aware, there is a date code on the box comprised of a five digit code followed by a 24hr time. For example, the freshest I am purchasing in California's central valley (read hot climate) has date code 18226. This translates to year 2018, day of the year 226. I usually quickly multiply the current month by 30 to get a rough idea that we're currently around day 270.

This being said, I generally have to dig for the freshest stock as there are actually boxes on our shelves from last year!

Question for the more experienced is, if we're titrating using the FAS-DPD method to check our levels, wouldn't this accurately reflect the need for more free chlorine when "stale" chlorine was used instead of fresh?

 

[mknauss]

Question for the more experienced is, if we're titrating using the FAS-DPD method to check our levels, wouldn't this accurately reflect the need for more free chlorine when "stale" chlorine was used instead of fresh?

Julian date is what you speak of.

Not sure what you mean by 'stale' chlorine. No such thing.

The 'old' bottles of liquid chlorine/bleach just degrade. To a lesser % sodium hypochlorite. So you just have to add more of the product to reach your desired FC level in the pool water.