Sand type

[bobarnold]

Hi all,
I have just finished building a small indoor pool at my house in the Philippines, I managed an Olympic sized pool for a couple of years in Australia and had bulk sand delivered whenever the filter needed topping up. Where I live here, most pools are using continuous spring water and 20 micron sand in bags is not available let alone any pool shops. Although I live along the Southern coastline, there is unlimited sand but the colour is a greyish black colour, not like the golden coloured sand I'm used to using. I'm worried that if I use this dirty looking sand, my pool water will always be discoloured. I suppose I could try it and see but I have become a bit lazy in my retirement days and don't like experimenting when it means a lot of extra work and disappointment. Do you think that after back washing and rinsing the sand to waste a few times, the water would go through colourless?

[Larry]

Hi Bob and welcome to the pool forums

The issue with filter sand is not the color but the composition of the sand. Filter sand is typically quartz (silica) and we have used quartz filter sand ranging in color from pure white to light brown. In our region the white sand is mined in quarries and then crushed before grading and washing. The colored quartz is naturally occuring and is less processed (and less sharp).

The best test for sand purity (without a lab) is to put some sand in a cup and add acid. If the sand foams then there is probably some calcium-based component making it unsuitable for pool filters. If the acid does not cause a reaction you should be okay using the sand as it is inert and won't react with the pool chemicals. You can use any strong liquid acid for this test. We usually use hydrochloric acid, but sulfuric or nitric acid work just as well.

Beach sand is not suitable for pools due to the high carbonate content from the broken up sea shells. If you can find a clean source for river sand you will be good to go.

Larry

[Larry]

A quick internet search turned up this list of companies selling silica filter sand in the Philippines

https://www.olx.ph/all-results/q-silica-sand/

If your local sand is no good then perhaps one of these companies could help.

Larry

[bobarnold]

Thanks for that info Larry, I drove past a tropical fish seller and stopped in the off chance he might know where to find suitable sand and bingo, he knew a guy that deals in swimming pool supplies, (probably the only one in the country). I was able to get his phone number and he can get anything I need locally except for the pure white silicon sand, it will come from the other side of the country but the cost is minimal.

[Larry]

Great!
I'm glad you got that sorted.

As far as chemicals go, you can easily substitute regular store-bought supplies for proprietary pool chemicals such as:
bleach for chlorine
borax for pH+ and algae control
washing soda for pH+
baking soda for alkalinity up

Larry

[bobarnold]

I'm still waiting for my delivery of silica sand from the other side of the country (six weeks ) but after filling the pool and adding some chlorine, I discovered I have iron problems with the water from my new bore. I learned from this forum how to deal with the brown water / iron issue however when starting my new pool pump without sand in the filter, it heated up and cut off on thermal overload as all good pool pumps should do.
Before consulting an electrician I would like to know if having no sand in the filter is making the motor overheat because the water pressure on the guage is almost on the red line which seems a bit strange to me.