stuamurr

The Algae is not in the water usuallynit is attached to the walls, ladders, crevices, holes of the pool furniture, so draining will for the most not solve your issue, check out the following forum for detailed information on treating algae. http://www.troublefreepool.com/algae-prevention-and-treatment-f11.html Stu

I think the key in this whole thread is santiser, you said you "came home a month later" which would suggest there has been no free santiser in you spa. Read the sticky posts on spa maintenance, in the chemical section and they will assist you better, I personally would advise dumping the water and carrying out a Decontamination as detailed by chem geek. Regards Stuart

The closer you get to to equator, the lower the tidal movement also, whilst theres plenty if sand beaches in the northern hemisphere, the tidal currents are that much stronger that particulates are mobilised creating cloudy water.

Thanks for the info, this is a picture of what I am getting frequently on the pool floor, is this therefore classified as mustard algae?

Leisurteq in the UK do a cracking wee Lovibond comparator with a chlorine and pH disc for £57.00, add your 100ml chaker bottle for TA & CH and you have a good wee balanced water test kit http://www.leisureteq.co.uk/pdf/008.pdf http://www.leisureteq.co.uk/water%20testing.html Regards Stuart

You need to get your TOtal Alkalinity right first with Sodium Bi-carbonate before raising PH with soda ash. Once you have a TA reading of 80-120 it will act as a PH buffer, stabiling the Ph which can then be corrected with ph correction chems. Bi-carb also raises ph slowly as you add it and adds the matt blue finish to water.

Thanks for that, the circulation system only runs once daily for 4 hours also, i realise this may well be an issue, do you think twice daily for a shorter period would be better advised? For example twice daily for 2 hours? Stuart

Hi, I manage a residential pool of 180,000 Litres / 40,000 US Gallons, it is a fibreglass hopper design with slopes in all directions to a flat shallow end and basin like deep end. For the last 2 months I have had a persistent. recurring algae problem, where brown algae gathers en-masse in the corners and slope joins, The pool has been superchlorinated with Calcium Hypchorite to 10ppm, then 15ppm and a copper based algaecide has been added, algae has been removed by vacuuming and a flocculant added added after extended backwash and rinse on each occasion. The walls and floor have also been extensively brushed. Typical Test Results using comparator: Temp 27-28 DPD1 1-3 DPD3 1.5-3.5 PH 7.4-7.5 TA 100 CH 200 CYA <50 Langelier 0.1 TDS ~600 Superchlorinate, Sweep, Hoover, Backwash, Rinse, Flocculate to remove the algae, but within days it is back as ever, and it really is starting to annoy me, I thought the addition of the copper algaecide would of called a halt to the algae blooms. Any advice would be appreciated. Regards Stuart