chlorine levels

[fhorta]

i'm batling mustard algae (brown dust looking deposits bottom of pool and walls) iread other posts and state that chlorine levels need to be about 20 to 25 ppm for chlorine to have an effect on this nasty stuff. i have a test kit that measures clorine, br, and ph, only. cl only goes to 5 or 6. how do i know if i have clorine levels of 20 to 25 ppms'.

not sure how to read this things. sorry for the elementary question and thanks.

[PoolDoc]

The problem you describe is the very reason that years ago I began promoting FAS-DPD testing, via the Taylor K2006. It's the most practical way to manage the range of chlorine levels needed on outdoor stabilized swimming pools.

For now, purchase a cheap OTO (drops turn yellow) test kit, and test your pH and chlorine. THEN add chlorine till your OTO sample turns orange instead of yellow. At that level, your pH test (phenol red) will no longer be reliable.

Hold dark yellow to orange chlorine levels, while brushing regularly.

Meanwhile order a K2006 test kit (the cheapest way to get DPD-FAS testing) using the Amazon links below. (CAUTION: only order if the link shows "Amato Industries, Inc.. " as the seller. Other sellers may deliver the non-FAS-DPD K2005.)

Report back with your test results. If you have stabilizer level info from your dealer, include that.

Ben

[fhorta]

Thanks. I bought some yellow treat and didn't do anything. Bouguht some de and psi goes too high at 13. Just can't get rid of this stuff. I'll try keeping it Orange for some days and order the kit.

[CarlD]

There's no easy magic cure. Just lots and lots of chlorine. The "treatments" do no good for algae.
To use DE in a sand filter do the following
1. Backwash
2. add about 1/4 to 1/3 cup DE through the skimmer.
3. Wait 30-60 minutes. If the pressure has not gone up, add some more DE.
4. Your goal is to increase PSI by 1 to 2 psi, no more.
5. If you increase it too much, just backwash to clear it and start again.

BTW, why do you think 13 psi is too high? My normal PSI is 20 and I backwash when I see it go past 25psi.

Carl

[fhorta]

I just assume 13 psi is too high becus when I feel water coming out of return jet feels weak. Like something preventing flow. When I back wash pressure feels strong again ane psi goes down to 7-8. I been going at it with this thing for almost 2 weeks maintaining high cl levels. Is this still considered normal or should I seen some results. Considering vacuuming to waste see if it works. Ill keep high cl and filter pump going for another day or so see what happens. Thanks.

[CarlD]

You are right: It should feel really strong at the return, whatEVER the pressure is! Here's a case where you know your pool best. If I saw 13psi, I'd be worried something was blocking my drains. If I saw 7psi, I'd be sure of it. But that's because for me, 20psi is normal and 25psi is when the force of the return flow drops---same 5psi increase as you have.

Now, we still don't know what you consider a "high" chlorine level. Nor do we know your CYA (stabilizer) level. The CYA level affects what the ideal Chlorine level is, both for shocking and for maintenance.

You can increase the range (but not the accuracy) of your OTO test kit with distilled water--only steam distilled, not ionized. Chain drug stores and supermarkets have it by the gallon. You can search our forum for the CarlD Shot Glass method, but here's how it works.
mix one shot glass of pool water with one shot glass of distilled.
Mix and pour into your test cell (the gadget with the scale). Whatever the chlorine reading is, double it.
Or, you can use 2 shots of distilled to one of pool water. Now whatever the chlorine reads, TRIPLE it! If the scale reads to 5, you can now measure to 15.
3 shot: You can measure to 20ppm!

But.....you MUST be careful measuring and mixing as your accuracy goes down with each level of dilution.

And, yes, you really do need to keep your chlorine level at (probably) at least 15ppm if you want the pool to clear. Now I opened to lime green "jello" on Saturday. It was disgusting Today's Wednesday and my water is clear. Why? I hammered it with chlorine immediately and kept at it, intending first to kill the algae, THEN clean it up. I'm now using Tri-chlor (gasp!) that I had left around because my pH is a tad high and my CYA (stabilizer) was non-existent. As a temporary fix, GIVEN MY POOL'S CHEMISTRY, they are ideal. The tabs keep a constant level of chlorine, are increasing my CYA (which I need), and lowering my pH, which I also need. So I'm not bothering to add baking soda or borax at this time, sticking with chlorine.

For another poster with CYA of 60 and a pH of 7.0, I STRONGLY recommended they stay away from Tri-chlor tabs and Di-chlor powder. They don't need a lower pH and a higher CYA level, it will make things worse. Yet it's still simple to do.

All the best,

Carl

[fhorta]

I have been adding 8 lbs of granular tri-chlor to pool (20k gal) in the evening and 4 lbs in am. Started doing this on 5/10. in the morning cl reads dark orange (before adding 4lbs). in the evening before adding 8lbs cl reads dark yellow. pump beein going 24/7. psi at 10 after adding about 1/8 cup of de.

i can only brush in the am and the evening when get home from work. dont want to get too excited but seems algae clearing just a tad bit.

just a little worried about alll the cya in this granular chlorine. ph reads dark purple but since cl is so high, ph is not reliable, right? hopefully progress will continue.

[Watermom]

Unless I missed it, I didn't see what your cya reading is. Do you have it?

[madwil]

If you've been adding triclor, you've been adding CYA; to much will make it harder to kill algae!
Recommend you use straight bleach or liquid chlorine, at least til you kill the algae and find out what your CYA level is

[fhorta]

i dont have a current cya reading. havent had the chance to get a water test. i just been keeping cl dark orange to dark yellow.

last night when i got home psi was at 12. felt return jet pressure and felt little weak. i backwashed and light blue-ish stuff came out. psi went down to 7 and return jet pressure felt stronger . added de again and this morning psi at 9. and jet pressure still strong.

the color of the stuff i'm dealing with has definitely changed from a noticeable brown for the most part. now when i brush i see a whitish cloud rise up from the pool floor. so there is definitely stuff still on the floor. i am wondering if its the residue of the granular chlorine i been putting in.

what i plan on doing is doubling the clorine this evening (16lbs) because i thought about cya levels increasing meaning cl levels need to increase too to have affect. going to leave pump on one more night. tomorrow will take water sample and tested. plan on vacuuming to waste after wards. can't think of anything else to do.

i will be taking some distiilled water home tonight and will do a cl range read as instructed. if i do get a reading between 15-25ppm, which is recommended to fight this stuff, will this be the actual cl reading regardless of the cya levels? in other words, a cl level of 15ppm is exactly that regardless of the cya levels? my T2006 test kit is on the way. thanks