I'll cover specs, then background, then test results, then questions...
Helping my brother get his pool open...
- 16,000 gallon I-G (3 ft shallow - 5 ft deep end)
- Sand Filter (forgot the brand, but I've seen the name here lots of times)
- Vinyl liner
- In-line chlorinator but currently has a supply of bleach
- one floor drain, one skimmer, 2 return jets
Brother bought a short-sale/foreclosure last spring. Pool had been closed several seasons, and was a black swamp from what he tells me. Using knowledge from a successfully pool experienced former neighbor and a slight scratching of the TFP surface near the end of the season, they thought the had it cleaned up. But from talking to them, I realize now that they did not. (Ex - water was clear, but if cloudy they shock it once and move on, not actually completing a shock process or OCLT). He did have one of the 6 or 8 item test kits, but didn't really know how to use it and was using strips.
They covered it last fall with the typical green mesh cover that many IG pools have, with the buckles down each side that strap it to the concrete, it's mesh so water gets through, etc. I do believe it was properly winterized.
Bro said they looked in it 2 weeks ago and it was still clear. We opened my AGP 2 weeks ago to sparkling water, and I strongly advised him to get his open ASAP. I had some time free today, and he wanted me to come over with my TF100 and do a proper test, and maybe help him open it since I was insisting he needed to get on it.
So we peel back the cover and it was BLACK. They swear up and down (and I believe them) that it was clear 2 weeks ago, but lined with a black film today (though the water actually was NOT cloudy...just a horrible black film on the walls and floor that then fragmented and shredded when brushed).
Test results with my TF100 (after the pump ran 20-30 minutes or so)
FC = 0 (no suprise)
CC = 0
pH = 8.5 or higher - maxed out the test kit
TA = 130
CH = 190
CYA = 0
The CYA is actually what started the whole day as he wanted me to verify what his strips were telling him (FYI, in this case, his strips and the TF100 were in total agreement on all tests that the strips could perform...BUT he is ordering the TF100 tonight).
We netted and scooped out as much of the crud that we could get after brushing the whole thing. Poolcalculator says hit it with 1.5 jugs of bleach but we hadn't checked the calculator yet so we actually dumped in 4 jugs. Sand filter didn't appear to actually be filtering anything (and after being neglected for years, it's not surprise...he said even last year it wasn't filtering out bugs, they were getting caught in the basket that is PAST the filter) so he was taking the top off and doing the "garden hose sand/crud/gunk flush overflow out the top" trick when I had to leave.
1) Is there really such a thing as "black algae"??? Does this sound like black algae? Could it have shot up in 2 weeks like this? To me, the stuff LOOKS like dead dark colored algae that would have grown after closing last year, but in skimming the forum I see people talking about BLACK algae. It is NOT "dark green" algae, no green to it at all from what I can tell. Also, there were a lot of earth worms intermixed with this algae...what's up with that?
2) If it IS "black algae", what do you do different from normal green algae?
3) I am NOT knowledgeable with sand filters (I have cartridge) - can someone please tell me what "Vacuum to Waste" means? Are there different "_____ to waste" phrases?
4) Any advice for how to tune up a sand filter that has been sitting for so long, or having such **** run through it for so long? Is the "overflow the crud out the top" idea the best one at this point? He does have several bags of filter sand laying around from the previous owners...should I just start over with new sand?
5) I saw someone talking about different types of Brushes for different algae types - did someone say a METAL brush? Can you really do that with a vinyl liner? Are there really different types of brushes for different algae?
6) Back wash frequency? Should he expect (with such a mess) to be backwashing multiple times per day?
7) I've got 50lbs of Tri-chlor pucks laying around that I can't use b/c my CYA is too high - with his so low, isn't he fine just filling his chlorinator with Trichlor pucks and turning it to high until his CYA increases? Would help him maintain shock level too...
8) I just saw the "turning your green swamp back into an oasis" post, and it said to fix the pH first! Well, we failed to do that...urgent to get it done right away? Or forget it now that we have started shocking?
Thanks in advance.