Hi I'm new to this forum. I am living in San Jose Del Cabo in the Southern end of the Baja Peninsular in Mexico.
We are living in a large house, on a golf course. We have an inground pool as follows:
approximately:
43 ft. by 22 ft. x 5 ft. deep.
Poured concrete with 3/4", blue glass tiles.
4 Eyeball adjustable returns.
2 Skimmers and 1 bottom return.
Each of the returns has a 2" pvc adjustable ball valves in the outside Pump House.
A Triton II, TR100, Sand Filter.

The pool is as I said, bordering on a Golf course and there are about 15 Benjamina (?) trees right beside and within 48" of the pool. These trees lose a lot of leaves into the pool. Lot's of spores i'm thinking?
So, I'm a previous owner of a Gunnite Pool in Ontario, Canada. I'm retired and every one in the family, 7 of us, decide that I'm to be the new "Pool Guy" for this pool in Mexico Every thing went great for a month got everything running (The pool had been empty for about 9-10 years) First problem that I had was the pump quit, I dignosed a bad rear bearing in the Woods motor. Replaced both bearings and everything OK. Next, the pump quit pumping. Needed a Pump rebuild kit. Ok, did that and solved that problem, but now I had a 127000 USG pool and it had gone 10 days without circulation and some serious ALGIE problems. Thank goodness, I found this great, amazing and knowledgable site.
I'm about a 6% understanding of Espaniol. I had found a good pool chemicals place here in San Jose but nobody speaks English and the hundred or so Spanish words I new did not cover Pool Chemicals. Any way I bought a Pentair, Model # 78 DPD "ALL IN ONE" TEST KIT. and some Dichlor, some Soda Ash and some Muriatic Acid. The pool was a deep swampy green by this time (The temperature at this time of year is still in the high 90s around here. I Superchlorinated the pool with the Diclor and also I had some other granular Chlorine, I'm not sure what else was mixed with it but anyway I got the water up to up to about 12 PPM Free Chlor. and kept it there for three days. I had the Sand Filter going 24 hrs / day and the water hadn't really changed colour, still deep green and the FC @ 12 - 13 PPM.
I thought maybe the sand in the filter was Tracking the effluent through without actually filtering it?? I decided that the sand was at least 10 years in the filter. I drained out the sand (600 Lbs of it) and hosed it all clean through the 6" access hole in the top of the filter, Installed new special fiter sand and started trying to filter the green stuff. Made no difference, the pool was still a deep Dark Green colour. I re-read through all of the posts on TFP and saw a post about Flocculents ? and was able to buy some at the pool store here. I shut off the pump and poured in 2 litres of the Flocculents right into the pool and set the system to re-circulate and let it run for 24 hours. Next moning I looked at he pool and noticed all of the dead algei were pretty well all clumped together. I put the filter into the waste position and pumped out all the junk. I repeated this in the next 24 Hours and now the water looks a beautifull blue again.
By the way. I could not find a way of checking the pool Cyanuric acid accuratly. TRhe only thing I could find here was some test strips that included a CA check. I don't think it was accurate and of course you have to know this info to treat your pool properly. Are there other ways of getting this info?
Thanks for all the information and experience on this great site. Terrymal

The easiest way to see if the filter is working is to watch the backwash water come out. If the filter is working the backwash water will be obviously dirty for a while before it clears up.

If you have been shocking with dichlor the CYA level is likely to be really high. Because of this dichlor isn't a very good thing to use for shocking.

Hi Jason: Thanks for responding. The reason I used the Diclor was because I had filled the pool with town water and thought that I would need to build up some CA for UV protection from the Mexican sun?

Yes that's reasonable for a new fill. Usually using pure CYA is less expensive, but if you have to add chlorine anyway then Dichlor will add both. Of course, until you build up more CYA your chlorine loss rate will be higher and that's part of what makes using Dichlor for this purpose more expensive, but other than cost there's nothing wrong with this approach. For every 10 ppm FC added by Dichlor, it will increase CYA by 9 ppm.

Welcome to TFP!

There is nothing wrong with using dichlor as long as you are aware that it adds CYA and you seem to be aware of this. Just stop using it once your CYA gets to where you want it to be and then start using unstabilized sources of chlorine such as bleach.