Horrible Algae After Opening Pool! Can't See Bottom

[Jason B]

13,000 gallon pool. I have 74% chlorine pro shock I'm about to use to do a triple shock today.
http://reviews.lesliespool.com/product-reviews/Pool-Chemicals/Pool-Shock/Leslies/p/14181-Power-Powder-Pro.html

I have a Hayward E65 DE filter.

My pool place is telling me NOT TO RUN THE FITLER while shocking it because of how bad my algae is and that my de filter will keep clogging. Again, the algea is so bad, you can see the bottom anywhere. The pool is dark green/black. I have a loop lock cover and shocked it in april, bottom was clean, but I guess that wasn't enough.

I'm debating on what to do about running the fitler?? Again, my pool installer says I shouldn't run the de fitler while shocking because it will clog over and over because of how green/black the pool is. I don't know if I should listen to this, or run it and keep backwashing a bunch of times.

Advice? I really don't want to wait 2 weeks for this to clear up. Do I need to run the filter ever when it's this dirty? or triple shock it with it off, and then double shock the next day, etc. etc.?

Side note, one year I had bad algae and used this product and it seems to help super fast.
http://www.swimpool.com/GreenPoolAlgae-Green_Treat.htm

[Bugman1400]

I think that product is the same as Green to Clean that I use in the 4lb jug. Follow the directions on the Green to Clean jug and you should be set. You may have to take apart your DE filter and spray down the grids and reapply the DE a few times. If you leave any of the coagulated algae trapped in the DE filter, it could comeback later after the chlroine level has dropped. I also have a DE filter and the Loop-Lock pool cover. I follow the same steps every year and the only time I ever had a problem was when I tried a short cut by not cleaning the grids on my DE filter when using the Green to Clean.

[Bugman1400]

ditto

[Jason B]

Ok, used the net to get all the green algae off the top and brushed the pool. Then I added 45 oz of 74% chlorine pro shock that I have leftover from last year. PH was around 7.7 before. It's been about 2 hours since I added the chlorine and it's getting lighter.

I still HAVEN'T turned the pump/DE filter on yet.

I also brushed the whole pool again, then a bunch of algae came to the surface again and I used the net to skim it off again. Latest pic. It's getting lighter, but I'm still afraid to turn the pump on with it this dark. Should I turn it on, or wait until tomorrow for after I add another 20 oz of shock.

Is the reason my pool place it telling me NOT to the run the pump because they think the chlorine will eat most of it up and be less work?

(I grew up with pool but never had it this bad where I couldn't see the bottom. I've used this site many times and use borax and baking soda for alkalinity and PH which has saved a lot of money just by using those instead of buying the official pool place stuff)

[chem geek]

These algaecide products you are both referring to are sodium bromide and will turn your pool into a bromine pool, at least for a while (maybe weeks or months, depending on how much you use). They are a workaround for too high a Cyanuric Acid (CYA) aka stabilizer or conditioner level since bromine does not bind to CYA while chlorine does. High CYA levels make chlorine less effective and if you don't maintain a Free Chlorine (FC) of at least 7.5% of the CYA level, then algae can grow faster than chlorine can kill it.

Again, using this product just works around the fundamental problem which is that you did not maintain the proper FC/CYA ratio, probably because you used Trichlor tabs and the CYA level rose as a result. The following are chemical facts independent of concentration of product or of pool size:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.

For every 10 ppm FC added by Dichlor it also increases CYA by 9 ppm.

For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.

So if a pool is using 2 ppm FC per day using Trichlor tabs, then the CYA will increase by 36 ppm per month if there is no water dilution. One can avoid the CYA buildup by using chlorinating liquid or bleach as their primary source of chlorine.

You will continue to have problems in the future if you do not lower your CYA level through water dilution.

[jkusmier]

chem geek is right, stop using stabilized chlorine sources. You might try letting all the debris settle to the bottom and vacuum to waste setting on the multivalve atop your filter to avoid repeated filter clogging/rinsing cycle while vacuuming. Might as well throw a hose in while vacuuming to begin immediate replacement of the water you'll lose while vacuuming to waste. Definitely speeds the process up.