Persistent algae, please help!

Jump to latest Follow Reply
K

Kantolapool

Member
May 26, 2020
24
Ravenna, MI
We moved 4 summers ago and were delighted to become the owners of a pool. The first 2 summers were decent but last summer and this have turned our pool into a money pit! We opened to a green pool on May 26 and have been balancing, shocking, cleaning and dealing with green, mustard, and maybe pink slime since then. We bought a Taylor test kit this year because we discovered the strips have been really off and we can't seem to get rid of the algae. Even though my water is now clear and looks good, pretty much every day I wake up to something on the bottom of the pool. It has been yellow, brown, pinkish white and poofs up like dust when you brush it. I have gone through 46 bags of cal hypo shock as well as 1 dose of yellow out and a few bottles of algaecide. I have brushed like a crazy person, vacuumed (pump to waste, backwash, filter to waste, then filter), and even changed the sand in my sand filter. I know my alkalinity runs high due to refilling with well water, but my chlorine has really been kept high with all that shock. Here are my Taylor test numbers from yesterday: ph 7.4, free chl 8.5, cc 0, alk 200 (corrected to 180 for cya), and cya 58. I used Utikem 50% algaecide concentrate last night and this morning found a bunch of what looked like dead algae (darker dust), so I did my vacuum procedure. This afternoon I have more mustard looking algae! What am I doing wrong? Please help!
 
Oh, forgot to say we have been swimming anyway because the water is clear and once I vacuum it looks great until later in the day or the next morning, but I have been diligent about washing swim suits each time and cleaning rafts and goggles with bleach water. Solar pool cover is used at night and has been put on after both shocking and algaecide, so that has been sanitized too I think. And here's a pic of what I described finding this afternoon--some in the shade and some in the sun.IMG-2747.JPG
 
Test results yesterday: Free chlorine 8.5, CC 0, Alk 200 (adjusted to 180 for cya), CYA 58
Test results today: Free chlorine 4.5, CC .5, Alk 200 (do I need to adjust for cya?), CYA 90
I did the CYA test twice because it was so much highter than yesterday. Maybe I read it wrong yesterday? Would the algaecide I used last night raise it?
So, I read the ABC's and the SLAM process. Obviously my CYA is way too high so I need to replace water, but then do I also need to lower my Alk before I SLAM?
 
TA is of no issue to SLAM. The adjustment thing is a pool store process. No need to bother.
Algaecide is either copper, ammonium, or sodium bromide based. Do you have the bottles to let us know what you added?
None of them will effect the CYA. Dichlor, Trichlor, and CYA effect CYA.
 
Here is a picture of the algaecide bottle. I have been reading more of TFP's articles and I think I understand my algae problem is due to my chlorine level having to be high to keep up with my high CYA level. So I'll be replacing some pool water to lower that CYA and preparing to SLAM. I'm off to the pool store soon for a water test (my Taylor kit can only test for CYA about 5 times without running out of test liquid) and to buy some liquid chlorine. If my calcium hardness is at 200, could I just use the cal hypo shock bags I already have to SLAM or will that raise my calcium hardness too much? Also, the previous owner of this pool used a FROG system and we have continued to use that. Should I get rid of that and just use liquid chlorine? I can't figure out what kind of chlorine is used in there, but maybe that is raising my CYA if it's Dichlor or Trichlor. Oh so much to keep straight! Thanks so much for your help!IMG-2762.JPG
 
That algaecide luckily just added a bunch of ammonia which takes a lot chlorine to neutralize it. Don't use any more of it.

The Frog is adding minerals (silver and/or copper ) and the tablets in it are Trichlor which is adding CYA. Remove both Pacs. They are not helping you and will create a mess later on, if not all ready.

Get your own test kit. You are welcome to get Pool Store tests, but we will not provide guidance based on them and all they do is confuse you with the results and their advice. You cannot mix TFP and pool store advice.

You can use Cal Hypo if necessary. Keep your CH level below 400 ppm.
 
Ok, got it on the not mixing pool store and TFP advice, and no more frogger or algaecide. I did have more algae this morning, so I vacuumed with pump to waste, backwashed, filtered to waste, back to filter and filled back up the water I let out with fresh well water. At the pool store I did watch the pool guy do the water test, and they had a Taylor kit fancier than mine and here is what they got today:
Ph 7.6, Alk 180, cya 70, chl 3, CH 200+ (He also tested my phosphates at 500 and wanted me to buy Phosfree but I did not. Yay for me, right?! :) )
So...do I let more water out and replace with fresh before I SLAM or do I just do it using my cya level of 70? That's a lot of chlorine to use according to your chart! Can I really lower my CYA that quickly? And a side question, is my pool store test accurate if it took me 20 minutes to get there, even though they used the same brand test kit that I have?
 
Your Taylor K2006 is one of the best test kits there is.

You can SLAM at a CYA of 70, but be sure to confirm that level with your own kit. Do get FAS-DPD refills heading your way now as you will be testing higher levels of FC. During the SLAM, use a 5ml water sample and each drop of reagent to clear is 1 ppm FC.

Not sure what you mean by lowering your CYA that quickly. Once you know your real CYA level, if you drain half your pool volume, you will lower your CYA by half.
 
Thanks for all the assistance! I will retest cya, but I will also try to keep letting out some water and replacing with fresh. I can't do that now in the afternoon sun or I expose my liner to too much sun, and we had problems with that before. And it's just too much water to let out all at once (30,000 gal. pool). I'll work on that today and tomorrow and maybe SLAM on the weekend. I really appreciate all your help!
 

Enjoying this content?

Support TFP with a donation.

Give Support
Update: I didn't end up SLAMming right away because with paying attention to the cya and chlorine levels our pool cleared up and looked the best it's looked all summer! However, after 2 pool parties in one week, and not keeping the chlorine up we discovered algae again. :( So we started the SLAM on Sunday night. Thankfully, my CYA is now around 50, so it's much more manageable with keeping the chlorine level high. Here's my question though. The pool floor has what looks like whitish or pinkish dust. It is not the same look as the mustard algae. I thought it was just the cal hypo powdered shock that settled overnight, even though we brushed and brushed when we put it in. Yesterday we just brushed it up and kept the chlorine high. But this morning the dust stuff was there again but we used only liquid chlorine all day yesterday. Is this some other form of algae or is it dead algae that has combined with the chlorine? We vacuumed it to waste this morning and it is there again tonight. I'm assuming we just keep up with the SLAM and vacuuming and brushing each day until there isn't any more of this stuff. Is that right? My combined chlorine has never been above 1 on any test so far.
 
Dead algae. It comes back because you kill more algae. Keep brushing, adding chlorine, and vacuuming. No need to vac to waste.
 
Kantolapool said:
The kids are anxious to get back in the pool
Click to expand...
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
 
Such good news! Thank you! Happy kids!!! Every day they ask me if they can swim.
Also, what, if anything, should I do about cleaning my sand filter? I have had dead algae every day and continued to vacuum to waste (because my cya is still on the high end and adding that new water helps that) so all that dead algae is going out of the pool not into the filter. And we just changed the sand a few weeks ago. Do I still need to do some kind of cleaning procedure after the SLAM?

A question as well about my solar cover. It is a super heavy duty (and heavy) cover that we have left off during the SLAM because it has been so warm already, we're not swimming, and due to all the adding chlorine, vacuuming and brushing. We did put it on the first night we added the most chlorine and dunked it in to kill any algae on it, but since then (Mon. morning) it has sat rolled up. My husband is concerned algae might be growing on it due to it being wet and in the sun. If I put it on tonight after my last addition of chlorine, do you think that's ok?

Please know how much I appreciate all your assistance!!!
 
Your sand filter should be fine. No need to deep clean this soon. You might consider it just before you close the pool for winter.

You can add the solar cover. Best if only over night. If it has any algae your SLAM level FC should take care of it.
 
So I've been keeping my free chlorine up to SLAM level for 9 days, and I'm still finding dead algae every morning. My free chlorine loss overnight hasn't been much at all, but today it went from 22 last night to 17 this morning, but only a combined chlorine level of 1. And the dead algae had an orange tint to it. We've been swimming but taking precautions to wash swimsuits and toys. I've vacuumed once each day. We've been brushing each day. I've kept testing my cya to keep the right chlorine level. Any idea if I'm doing something wrong or if I need to do something different?
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply