Firstly, thank you to everyone who shares their knowledge here. I have spent hours reading posts over the last few weeks and it's been a great education for me.
I have a 17ft swim spa, so it's bigger than a hot tub but smaller than a pool. Volume is about 2000 gallons. Bromine system with a chlorine generator. Bought it last August. Lots of fun, no major issues.
From my reading here I have learned a few things that demonstrate how bad the advice was from the pool store after installation..live and learn...
- my FC levels have always been low (1 or lower). The advice of "check it once a week" with a test strip is clearly not enough for a bromine swim spa that is in the sun. Whatever FC is generated from adding oxidizer burns off that day. Weekly checks leave many days where FC was probably very low.
- the generator is a nice idea but it really can't keep up with both bather load and sunlight combined.
- I have since switched to using Clorox as my oxidizer , putting it in basically every night, using the pool calculator to target an FC level of 5. Hit it over the last couple of days so I am getting a feel for that. The water was slightly cloudy before I moved to Clorox, it's clearer now.
The possible algae...
- I started seeing what looked like small globs of dirt on the bottom of the spa last week, a week or so after a pool party the kids had (heavy bather load)
- tried cleaning the filter etc but it persisted
- created a basic siphon using tubing from the local hardware store..it tends to break up very quickly into a wispy sort of cloud but was able to get most of it out...but it returned overnight each time.
- pool water is otherwise clear, easy to see the bottom, crystal clear when you go under water with googles on.
- because I learned my lesson too late and low FC levels have occurred, plus 4 kids using it a number of times on top of regular bather load, I have to think Algae is a real possibility.
- given I have a bromine spa I think I have two options
1- shock using instructions I have found in these forums. I would plan to add enough bleach to take FC over 10 and watch for overnight loss. I have a test kit on the way, they are not as easy to find in Canada. Question- given I have a bromine spa, any alterations to the usual a shock instructions I need to know?
2- I could dump the water. Since it's essentially a big spa and not a pool, a water change is an option. But...if it is algae a simple water dump won't solve the problem I would still need to shock I would think, so I am not sure this option gets me very far.
I am open to other thoughts and input. I kick myself for not getting educated sooner but I believed the idea that I had a "self cleaning" spa and did not pay enough attention to water chemistry., plus the guidelines I were given really seem woefully inadequate given all that I have learned on these forums. I have found the learning here very beneficial, it's more than I have ever learned from the pool store folks, and I am moving towards using the simple products outlined in the BBB method to manage my water.
Thanks all, advice appreciated