I'm just getting used to my fiberglass pool. My previous pool was vinyl. When I entered my test results in PoolMath, it says the ideal levels is 350-550ppm. I tested 280ppm. I was under the impression calcium wasn't important unless you had an older fiberglass pool with calcium in the gel coat. Is it important for all fiberglass pools and is it the ideal levels as in PoolMath and under the recommended levels on this website?
Calcium and Fiberglass Pools
- Thread starter Homebrewale
- Start date
- Jun 22, 2014
- 52,049
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
That is correct. More than anything the recommend calcium level is simply to help prevent potential staining and for those owners with certain equipment that have specific CH requirements. There should be no worries about etching to the surface like plaster. While the APP lists 350 as ideal, even a min CH level of 250 should provide plenty of stain protection for the gelcoat. You might check your heater's owners manual as well though.
The issue I have with checking the owners manual is that I've got into the mindset that equipment manufacturer recommendations differ than TFP recommended levels. For example, Pentair recommends for my SWG to have levels of 30-50ppm for CYA (TFP is 70-80) and TA of 80-120ppm (TFP is 60-80). For the most part, the recommended levels for the SWG and heater are the same which isn't surprising since both are made by Pentair. One difference is the ideal salt level for the heater is 3200ppm and for the SWG is 3600ppm. Both the heater and SWG recommendation for CH is 200-400ppm.
- May 3, 2014
- 62,717
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
The requirement for a CH level in your pool water with a gas heater comes from the days of Steam Boilers. Now, a gas pool heater is no steam boiler, but a small amount of calcium would be a good idea.
I would target 100-200 ppm for your situation.
This assumes you do not have waterline tile with cement grout.
I would target 100-200 ppm for your situation.
This assumes you do not have waterline tile with cement grout.
- Jun 22, 2014
- 52,049
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Good point Marty, I forgot about that one. Another reason TFP elected to list a minimum CH level to cover various FG pool scenarios.
As for the CYA and TA numbers from Pentair, remember those are their generic industry standard recommendations. Sure, you can use an SWG at 30-50%, but owners will find their pump run time and/or cell output having to be much higher to keep-up with the FC loss from the sun. Owners can have a TA of 80-120, but soon may find themselves adding acid every day or two to control the pH, not to mention increased scaling on the cell plates. Those are just a couple examples you've probably heard here before.
TFP takes into account many more variables the others simply don't have the time (or initiative) to do.
I understand they are just generic industry standard recommendations. That's why I said I'm in the TFP mindset to ignore them.