SLAMarama... Need Advice w/ Algae Problem

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speedwater

speedwater

0
Jan 5, 2017
29
Austin
I'm a new pool owner fighting an algae problem.

The pool was built in the 60's and needs to be resurfaced. Because of that, the gunite is stained and it is difficult to discern the color of the algae that settles out on the floor. I have a sand filter w/ sand that was replaced about a year ago (before we purchased the home).

I have a LaMotte ColorQ for daily testing and a Taylor k155a FAS DPD I bought for SLAMing. I've been using software from Perfect Pool and Spa Pool Care Software with ranges aligned to the recommendations on TFP and the calculator here occasionally (mainly to calculate additions for SLAM b/c perfectpool doesn't want to deal w/ chlorine >10).

I can get the water looking clear, testing correctly in all ranges, etc. But when I run my Dolphin Nautilus Plus it kicks up a bunch of green algae and I have green in the vacuum filters. I can also brush and kick up plumes of green and turn the water into a green swamp. So I SLAMed following the instructions here....get back to clear, but still have the same issue.

I'm currently SLAMing now paying extra attention to the details...it's been about 5days. I have NOT been vacuuming to waste and have instead been brushing daily and backwashed the filter. The SLAM instructions say vacuum or brush once a day...I've chosen brush. I also added some DE to the filter per the instructions here (1lb PSI rise, etc) to hopefully speed the process. Current free chlorine is 15 and combined chlorine has shown 0 for two days on the Taylor test (assuming I am doing it correctly. 2 scoops, add chlorine until clear to determine free chlorine, add 5 drops of #3 reagent to same sample and it should turn pink but mine stays clear so CC=0). I haven't done an overnight FCL test..was waiting for the water to clear.

So here's my question: Should I let it all settle out and then attempt to vacuum to waste instead of continuing to brush and kick it up hoping the filter will catch it all? The only thing that makes sense to me at this point is the algae is dead, and the material is just too fine for my filter to filter out. It's hard to tell the exact color of the material due to the bottom color of the pool. It's definitely not white, it could be brown, but it certainly turns the pool green when you kick it up. Everything I read here, green=not dead but my CC of 0 would indicate otherwise (unless I am somehow screwing up the CC portion of the test but I don't think so).

I've avoiding vacuuming to waste just b/c of dealing w/ the runoff, loss of water, etc. but I think that may be the missing link.

Please help!

Mitch
 
I'm a new pool owner fighting an algae problem.
Click to expand...
It's definitely not white, it could be brown, but it certainly turns the pool green when you kick it up.
Click to expand...

That is the key right there. Green algae is live algae
The reason to brush is to disturb the algae and break algae biofilms so the chlorine can better kill the algae off

CC's are an indication that the chlorine is working on something, but the CC can disappear rapidly with sunlight or being broken down by the FC. CC can also rise and fall rapidly. So 0 CC does not by itself mean the process is finished. Thats why there are 3 measures for finishing the Slam. 0 CC, clear water and passing the OCLT. So at the moment we can only say you have passed 1 step, the 0 CC

Can you post all of your test results?

Please fill out your signature too


Oh and nice to have you with us :)
 
Lets start at the beginning. Here is the link to the SLAM. Please print it out so you have easy access to it:

Pool School - SLAM - Shock Level And Maintain

The most important part of it is M-maintain as in maintain your FC at SLAM for your CYA.

I would vacuum to waste to get what is on the bottom out. After that brush at least once a day. Try to two if you can. Not fun but.......once you are done with the SLAM you should not have to do this again if you keep the pool balanced the TFP way.

Good job on adding the DE to the sand. That should help once the algae is dead BUT it is not dead yet.....lets get SLAMing!

Kim:kim:
 
Ok the ph test may read high with FC over 10. I know it does with the taylor drop based tests, not sure if/how it will affect the ColorQ

I would round up your cya to 40 and therefore maintain your fc at 16 for the slam

Are you running the filter 24/7?

Vacuum to waste or vacuum to filter doesn't matter, if you want to vacuum instead of brushing. Personally if you do I would just vac to filter and backwash when the filter rises 25% above clean pressure. It should rise fast with the DE in there so keep an eye on the pressure
 
Just checked and lamotte says the ph will read high with an FC of over 8ppm
Also FC of over 10 will affect the alkalinity test

This is the reference I used: http://www.vendart.com/images/pdf/ColorQ_Testing_Tips.pdf

I also found this in another post which I thought you may find useful
Just got an email back from LAMotte tech support about the ColorQ. This is what they had to say:
The ColorQ has accuracy of ± 0.1ppm on chlorine and pH, ± 15ppm on alk,
and ± 20ppm on hardness and cya. The cyanuric acid test is a difficult
one with a meter like the ColorQ, since it is a turbidity style reaction.
(it gets you in the ballpark on cya). The chlorine and pH tests are great.
The alkalinity test has been performing very well, my ColorQ has given me
readings within ± 5 to 10ppm on alk. Hardness is another tough one, but
the ±20ppm isn't so bad when you consider the wide range of hardness from
200 - 400ppm. So all in all, it is actually a great meter for that price
Click to expand...
 
Yes, running the filter 24/7. PH was 7.7 before I started and I added some acid to lower it per the calculator but forgot to measure before I started the Slam, but per the math should have been in range. My last CYA before starting was mid 50s so was targeting 20 and I've been north of 16 for probably 5 days until today. I'll start vacuuming to filter and see if that brings some improvement. I've Backwashed once already when pressure climbed from 19 to 25 and then added more DE.

Sent from my SAMSUNG-SM-G925A using Tapatalk
 

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Caco said:
How often are you testing and dosing the pool with chlorine?
Testing more often is better as it keeps you up at your target level. This is one of the easiest ways to make the process quicker
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Couple of times a day at the beginning...lately more like once a day but I'll test more often moving forward. It hasn't been consuming chlorine very rapidly and hasn't been below 14 in any test since I started late last week.
 
I think you need to do an OCLT so we can gain some insight into your pool
The test procedure is below, but it is pretty basic

After dark test your fc and dose up to target
After 30 mins retest to ensure you reach target and note that number down
Leave pump going all night
Before sunrise test your FC and CC levels
You are looking for max 1ppm FC loss and no CC

https://www.troublefreepool.com/content/136-perform-the-overnight-fc-chlorine-loss-test-oclt

This should confirm if you still have algae issues as only organics or sunlight will consume chlorine. Done at night then the only thing that can lower your FC is organics

BTW have you run blanks on your colorq lately to calibrate it? (not sure if your model has that feature)
 
I'll do an OCLT tonight and report back. I run blanks on the ColorQ every time I test. Process is to run a blank, then add drops to that sample to test FC, then additional drops for Total chlorine, then fresh samples for PH, TA, etc.

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
Hello Speedwater. :wave: You've received good advice thus far, and our chilly weather the next couple days will help you retain FC. Personally, I wouldn't get too wrapped-up in the DE yet. DE is used to help filter-out the dead algae near the end of the process to help with water clarity, but you're not there yet. That much green indicates live algae that needs consistency (FC level) to kill.

Your note in post #1 confused me a bit though:
Taylor test (assuming I am doing it correctly. 2 scoops, add chlorine until clear to determine free chlorine, add 5 drops of #3 reagent to same sample and it should turn pink but mine stays clear so CC=0)
Click to expand...
But to confirm, with the FAS-DPD powder & drops, use the following to test your FC:
Use a 10ml water sample, add one "hefty" scoop of powder, stir and count drops until the sample turns clear and multiply drop count by 0.5 (standard method)
Click to expand...

Keep plenty of HEB's regular Bravo or Wal-Mart's Great-Value bleach on-hand to maintain that SLAM FC level and you should see changes soon. Let us know if you have anymore questions.
 
My Taylor instructions say 2 scoops of powder. I've elsewhere read 1 heaping or 2 level scoops. I've stuck with two level because to me that's repeatable. How much is "heaping"... Seems too subjective.

What I was a little unsure of was just the CC portion of the test. Instructions are a little vague on if you add it to the original sample after you turn it clear or if you add to a fresh sample. It turns a fresh sample yellow. I've yet to see it turn the tested sample more than just a really slight pink which made me question if I was doing it correctly. Based on what I'm learning here, my CC must be rapidly getting consumed by the FC and I'm just not catching the timing in my testing.

TAYLOR INSTRUCTIONS
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I have not followed your thread but I will tell you the amount of powder is not at all critical.......don't worry about it.

Your CC"s test should be using the just completed sample when you tested for FC. That you are getting just a faint pink is good and also pretty typical. You are doing the test correctly.
 
If you're more comfortable with 2 level scoops, that's fine. For the CC test, start adding the R-0003 reagent to the same water sample right after you've recorded your FC test. If the sample remained clear, you're good. If it changed back to pink, then do the R-0871 drops until clear (again) and record the CC level. Anything at .5 or below is considered basically zero and good for TFP purposes.

Pool School - Extended Test Kit Directions
 
Sounds like you have a handle on the testing now. For me personally, when I'm sure it's algae, I don't invest a lot of time with the CC test until I know the water is changing from green to clear and ANY visible algae is gone. After all, during a SLAM, one of the passing criteria is "clear water" which includes both cloudiness and/or green. So by focusing your efforts on brushing daily, backwashing when pressure increase by 25%, and most importantly maintaining the proper FC/SLAM level, you should see the results you expect.

The only "unknown" I see from post #1 is the sand filter. While it appears to be new, it may be difficult to know what the previous owners did during their pool care. By that I mean did they ever do a thorough deep clean as described on the TFP Deep Cleaning a Sand Filter If they used pool store products, they could've done something to compromise the sand's ability to filter properly, so you might consider the deep clean if you don't see some positive improvement soon.
 

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