Second year, I have mystery algae in the vacuum hose.

Fezick

Member
Aug 25, 2019
24
Clovis California
Ok, so third season of the pool. Second year I have had to SLAM the pool due to algae growing in the vacuum hose. Seems strange. Just started the SLAM tonight. Here is what my water reads most of the time:

CYA 40 (maybe 50 once in a while but usually around 40)
Hardness 350
ALK 85
PH 7.5-7.7
CH 4.5-6.5 (depending on if its time to add liquid chlorine or if have have just added it)

Pool info, pebble pool, approx 35,000 gal, dual skimmers. Pool filter runs 6.5 hours a day (three of that is the vacuum) not including the time it runs when we are swimming and the water features are on. (one of my features is tied in to the filter pump so when that feature runs the skimmers also run)

So here is the weird thing. My pool water is clear. Filter cleaned before the season opened. (both years) Cartridge filter. As I am swimming around the pool I usually see the little spot of green algae just above the pool water line on the grout and that is what usually tells me "uh oh I better look at that stinkin vacuum hose". I do and sure enough I will find one portion of the hose (usually a part that is on the top of the water more often) and it will have just the slightest signs of algae in the ribs. So I usually pump up the chlorine a bit (and maybe oxidize it with some non chlorine oxidizer) and it goes away. Then I go and scrub the grout lines and all is well. Until, sure enough we get a 102 day or so and I see the little algae pop up on the wall again and poof, algae in the vacuum hose but now its in multiple hoses. At this point I SLAM away, reset my water levels and off I go.

All this is to say, what the heck am I missing? I even use some of the phosphate killer to keep those phosphates at a minimum. (I am not a huge believer in that stuff but low phosphates can't hurt right???) I keep my water in the sweet spot and yet it seems at this time of the year I still get a run of algae that I have to SLAM which keeps me out of my pool for multiple days at a stretch. Thanks in advance for any ideas and for all the help everyone has already provided on the water chem side of things. I am a bit of a water nerd and probably test more often than most. (about every other day as I am adding liquid chlorine at least that often if not daily to keep it in the sweet spot) Am I not running my vacuum enough? Is there some other glaring issue that causes this algae build up only in this specific area?? Can anyone help me with my quandary???

1595571524398.png1595571524398.png
 
Last edited:

mgtfp

Bronze Supporter
Mar 5, 2020
484
Melbourne, Australia
If your CYA is usually around 40 and sometimes 50, then I'd just call it 50. If in doubt, round up to the next ten. And 4.5 is quite close to the min for CYA 50, you should probably keep a larger safety margin to the min.

How often do you use the vacuum hose? It probably doesn't get flushed with fresh chlorinated water often enough and algae can get a hold in it.

Is it a segmented hose that you can take apart and brush the segments? Brush it as thorough as you can and make sure it gets a good soak in your SLAM water and multiple good flushes. Add a few weights do that it's really submerged. Or, if it has a history of getting algae infected, just replace it.
 

Fezick

Member
Aug 25, 2019
24
Clovis California
If your CYA is usually around 40 and sometimes 50, then I'd just call it 50. If in doubt, round up to the next ten. And 4.5 is quite close to the min for CYA 50, you should probably keep a larger safety margin to the min.

How often do you use the vacuum hose? It probably doesn't get flushed with fresh chlorinated water often enough and algae can get a hold in it.

Is it a segmented hose that you can take apart and brush the segments? Brush it as thorough as you can and make sure it gets a good soak in your SLAM water and multiple good flushes. Add a few weights do that it's really submerged. Or, if it has a history of getting algae infected, just replace it.
The vacuum hose is on the robot that sucks up the debris from the bottom of the pool. It is on every day for three hours. Any ideas as to why that is the only area i see an outbreak when I see the few algae patches on the grout too? They seem different but related somehow? Fyi when I do a slam, I always pass the first night at a drop of less than one so I assume there is not a ton of stuff in the water to kill right?
 

mgtfp

Bronze Supporter
Mar 5, 2020
484
Melbourne, Australia
With robot, do you mean a suction cleaner that gets driven by your pump? Might help if you'd put all your equipment into your signature, that makes diagnosis a bit easier.

Is the cleaner and the hose permanently in the water or do you take them out after running the cleaner? Is your cleaner running during your slams, i.e. does the hose get flushed with slam water?
 

Fezick

Member
Aug 25, 2019
24
Clovis California
With robot, do you mean a suction cleaner that gets driven by your pump? Might help if you'd put all your equipment into your signature, that makes diagnosis a bit easier.

Is the cleaner and the hose permanently in the water or do you take them out after running the cleaner? Is your cleaner running during your slams, i.e. does the hose get flushed with slam water?
Yes suction cleaner runs with one of my pumps. Runs every day for 3 hours out of the 7 hour cycle i run in the mornings. Stays in pool 24/7. I leave it in during slam. Yeah I need to update my signature.😄
 

BadDogPSD

Gold Supporter
May 24, 2020
112
Reno, NV
Yes, that's your cleaner hose. Sounds like you need to raise your FC levels. Are you adding liquid chlorine daily? I know Clovis is hot & sunny in the summer.
 

Fezick

Member
Aug 25, 2019
24
Clovis California
When you say that you SLAM the pool, are you meeting all 3 of the completion criteria?

You can use your pool during SLAM.
Yes I slammed it according to to specs. I'll see how it looks over the next three days as I will have family in the pool alot. I'm hoping the slam cleared up the hose but if not I'll have to slam again but at a higher level I guess.
 

LFrankow

LifeTime Supporter
Sep 27, 2012
608
Medicine Hat, Alberta
run your vacuum as long as your pump, if the hose is full of FC = 5 water algae will not grow, if the vacuum stops air will go to the top side of the floating hose in the pool and algae will show up. I do like Dave said take the hose out of the pool once done, but if I couldn't I would keep circulation thru the hose all day.
 

Fezick

Member
Aug 25, 2019
24
Clovis California
run your vacuum as long as your pump, if the hose is full of FC = 5 water algae will not grow, if the vacuum stops air will go to the top side of the floating hose in the pool and algae will show up. I do like Dave said take the hose out of the pool once done, but if I couldn't I would keep circulation thru the hose all day.
FC been at over 6 for easily a week after the slam. Stuff still in the hose but I'm assuming it's now dead algae that is caught in the ridges. Can't take the hose out every day as the connection location requires me to be in the pool. (And I'm not jumping in daily at 5am to put it back in for the daily cycle). Might pull it out for a couple days just to see if drying it out completely makes it easier to get the dead algae out of the ridges. Not sure running the vacuum 24x7 is an option all summer plus that would also run my waterfalls that would shoot my PH through the roof. Thinking my CYA might be a bit higher than either I or the pool store has tested, so I'm gonna test it like 5 times to get a good average and stay in the high side of target as much as possible.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,435
Fletcher, OK
I have a suction side cleaner "the poolvergnuegen" and in 5 years I have never had algae in it but it does run 6 to 8 hours a day and I have a SWG.. I have my CYA at 80 and my FC between 6 to 9 at all times...

 

kellyfair

Gold Supporter
Bronze Supporter
Jun 29, 2016
2,925
Tampa, FL
If you are getting spots of algae in your pool whether it starts in the hose or not, your FC isn’t high enough. It’s just not going to grow if conditions aren’t right.
 
  • Like
Reactions: YippeeSkippy

Fezick

Member
Aug 25, 2019
24
Clovis California
I have a suction side cleaner "the poolvergnuegen" and in 5 years I have never had algae in it but it does run 6 to 8 hours a day and I have a SWG.. I have my CYA at 80 and my FC between 6 to 9 at all times...

My guess is the difference is water temp. You're in OK. I'm in central cali and also have a dark bottom pool. We get the water easily in the 90+ degree for many months. Perfect for algae to grow.
 

Katodude

Silver Supporter
Aug 22, 2017
1,191
West Palm Beach/Florida
Nah, temp will not make that much of a difference. Just like any SLAM you have not eradicated the algae in the hose. Take the hose out of the pool and blast a pressure washer through it. Then cap one end and put a HIGH concentration of chlorine to water in there. Do that twice.

Or just go buy a new hose that does not have any algae in it.
 

kellyfair

Gold Supporter
Bronze Supporter
Jun 29, 2016
2,925
Tampa, FL
My guess is the difference is water temp. You're in OK. I'm in central cali and also have a dark bottom pool. We get the water easily in the 90+ degree for many months. Perfect for algae to grow.
My pool rarely dips below 90 for weeks at a time. It was 93 when I was in it on Saturday.
 

Fezick

Member
Aug 25, 2019
24
Clovis California
In guessing the swg helps keep the fc a bit more consistent. I'm trying to decide if I slam again, pull the hose and try a deep clean on it or buy a new hose. Hose is only on its 3rd year though.