Buying house with a green pool

[ric]

I'm buying a house that has been vacant since last summer. The pool is dark green and the realtor says we need professional help. The pool place said I can do it my self and they'l walk me through it.

It can run us up to $450 to have someone come and clean it. Is it worth it? We have to get it cleaned ASAP (within one week).

Any suggestions?

[chem geek]

You can absolutely do it yourself. First, you should physically remove as much debris as possible using a leaf net or equivalent. Then, you will need to add a LOT of chlorinating liquid. See this link for an example. Basically, you will keep adding chlorine to maintain a high chlorine level until all the algae is gone. You should test the water for Cyanuric Acid before you get started -- if there is none in the water, then you'll want to add some, probably by using some Dichlor, so that the chlorine won't break down in sunlight (you don't want to add too much CYA, however).

The pool store may want to sell you algaecide which will cost more and may go faster, but you don't have to do that unless you want to. Chlorine alone will clear a pool (along with filtration and backwashing). Be sure to brush the sides as well to expose all the algae to the chlorine.

Richard

[ric]

Thanks for the encouragement. The realtor called several pool places that went to the house and they said that what is really needed is an acid wash. He told me the cheapest one was $750. Needless to say I was floored.

An analysis of my water (which I obtained surreptitiously) is as follows:

FAC & TAC - 0

pH - 7.6

TA - 120

Hardness - 190

Phosphates - 2500

I told my realtor that $750 of my hard earned money is unacceptable and that I was willing to take time off from work to get this done myself if necessary. He said that the only way to go according to the pool service companies best judgement was an acid wash.

I don't know if I'm being unreasonable and stubborn. My wife seems to think so; but then again; its not the first time she's thought so. Do I have any viable options if the walls and the bottom of the pool are covered with algae in some placesup to 1/4 " thick?

[chem geek]

Well an acid wash would only make sense if the plaster was covered with black algae or metal stains or something along those lines. Even then, such things can be cleaned by other methods though if it's really that bad then perhaps that's why they are saying an acid wash is the way to go. If it's just green algae (similar to the picture I linked to), then that shouldn't require an acid wash though will require a lot of physical removal, filter cleaning, chlorine, and brushing.

The phosphates level is on the high side and after killing off the algae it will likely go higher so another option to prevent continued algae growth would be to use a phosphate remover, but that can get very expensive for the level of phosphates you have now plus what you will have as you kill off the algae. A partial drain/refill can help and in fact if you can vacuum to waste then you can remove the algae and partially drain the pool at the same time. You don't want to drain it very far, however, and will want to refill with fresh water (if you drain below the skimmer, then you need to turn off the skimmer input and only use the floor drains though I fear they may be quite clogged at this point -- physical removal of as much as you can do is the first thing to do).

You didn't measure the Cyanuric Acid (CYA) level. That's important since not having any would make chlorine addition breakdown with the UV rays of sunlight. You don't want too much CYA -- up to 30 ppm should be plenty. So test the CYA level and you can use Dichlor as a fast-dissolving source of chlorine where for every 10 ppm FC added by Dichlor, it will also add 9 ppm to CYA. Then when the CYA is where you want, you switch to using only chlorinating liquid (or unscented bleach such as Clorox Regular, but if you can get 12.5% chlorinating liquid from your pool store, that's more efficient).

Richard

[mr_clean]

I agree with Chem Geek that you do not need to acidwash to clean this up. I have seen pools looking like a duck pond cleaned up with chemicals, a couple filter cleanings & lots of brushing.
or
Emptying pool & doing chlorine wash just like you would acid wash starting fresh with no phosphates.
or
Emptying pool & using highpressure rental water machine to cleanoff algae.

just depends on what you want to do

[jillebeanz]

I will try to chlorine this year as the green stuff is so expensive! I will go today to purchase the chlorine and will give it a try. will let you know how it goes...

[Jillebeanz]

Well I took a water sample to my local pool store and this is what I have
FAC/TAC 0
TB 0
WATERPH 8.0
TA 90
CH 520
CYA 100
TDS 1200
C/I 0
P 0
I was advised to ad muriati acid and wait 4 hours then add power powder plus and its been 5 hours and I already see a difference!!!! Let me know if you think this is Ok!