Switching from Stabilized to Non-Stabilized Chlorine Pucks

[erinkalogris3]

Hi there! We purchased a home in October with an 11,000 gallon inground fiberglass pool. The previous owners seemed to rely pretty heavily on trichlor pucks - when the pool was opened, we found the CYA was 129. We partially drained the pool and refilled, and our CYA levels are within normal limits now. We obviously don't want to do that again anytime soon, so I'm going to stay away from trichlor pucks. I've been using liquid chlorine, but I can't imagine I'll want to pour some in every single day. I already know that using unstabilized pucks in the automatic chlorinator is a no-no (could go boom), so I won't be doing that.

My question is: is it okay to switch to unstabilized chlorine pucks and use them in a floater to help keep chlorine levels up and slightly minimize liquid chlorine? Would that cause any bad reaction? Additionally, a lot of the unstabilized chlorine pucks I see say to only put these in the skimmer - what's best practice? Skimmer or floater?

I recognize that unstabilized chlorine pucks will increase calcium hardness which is fine for me currently, because our calcium is low. Also open to recommendations on recommended calcium hardness levels and if they differ for fiberglass pools.

Thank you! I'm a newbie here, so I appreciate the help.

 

[PoolStored]

Do not put any pucks in the skimmer. Use a floater.
Unstabilized pucks replace the CYA in the trichlor with Calcium. You still have the same issue with calcium...when it gets too high, you need to replace water to lower. When Calcium is high, you face calcium scaling.

A fiberglass pool does not need calcium, unless you have a tile waterline or gas heater. If you have tile or heater, CH of 250 is just fine.

If you know that you face potential scaling with high ch, and you understand that you will at some point need to replace water, then use the unstabilized chlorine.

I'd get an SWG.

Calcium Scale - Further Reading

www.troublefreepool.com

 

[Bperry]

Hi there! We purchased a home in October with an 11,000 gallon inground fiberglass pool. The previous owners seemed to rely pretty heavily on trichlor pucks - when the pool was opened, we found the CYA was 129. We partially drained the pool and refilled, and our CYA levels are within normal limits now. We obviously don't want to do that again anytime soon, so I'm going to stay away from trichlor pucks. I've been using liquid chlorine, but I can't imagine I'll want to pour some in every single day. I already know that using unstabilized pucks in the automatic chlorinator is a no-no (could go boom), so I won't be doing that.

My question is: is it okay to switch to unstabilized chlorine pucks and use them in a floater to help keep chlorine levels up and slightly minimize liquid chlorine? Would that cause any bad reaction? Additionally, a lot of the unstabilized chlorine pucks I see say to only put these in the skimmer - what's best practice? Skimmer or floater?

I recognize that unstabilized chlorine pucks will increase calcium hardness which is fine for me currently, because our calcium is low. Also open to recommendations on recommended calcium hardness levels and if they differ for fiberglass pools.

Thank you! I'm a newbie here, so I appreciate the help.

For a short time if your calcium is is low, but if it gets too high, you’re in the same trouble as using the other pucks in that you’ll have to drain the water to get rid of the extra calcium before you start to get scaling and deposits all over the surfaces.

Also warning! Do not put Cal hypo tablets in a floater that had tricolor tablets in it! mixing those two chemicals can make a violent reaction. Go buy a separate floater just for those tablets.

Eventually, you’ll need to switch to liquid chlorine to avoid the problems of those tablets and after getting tired of lugging jugs of chlorine around you’ll switch to the saltwater chlorine generator. Or…You can also just skip all that hassle and switch right now

 

[pjt]

I can't imagine I'll want to pour some in every single day

Get a SWCG and never look back.

 

[fastrunnerdude]

Do not put any pucks in the skimmer. Use a floater.

Why shouldn’t you put pucks in a skimmer? I primarily use LC and have a stenner pump that pumps it into my system downstream of the filter and in the summer I’ll sometimes supplement with some stabilized pucks in the skimmer basket. I put them in the skimmer basket so the LC and pucks don’t come into contact.

We get enough rain that diluted the pool and using some pucks keeps my cya at appropriate levels and reduces # of trips I have to make to pick up additional bulk LC to add to the tank for my stenner pump.

 

[pjt]

Why shouldn’t you put pucks in a skimmer?

Trichlor tabs are very acidic. You don't want acidic water entering your system, especially if you don't operate 24/7. The tabs would create a low pH/high chlorine mixture in your skimmer and pipes.

I primarily use LC

reduces # of trips I have to make to pick up additional bulk LC to add to the tank for my stenner pump.

I would **highly** recommend a SWCG, especially with a 40k gallon pool in our area. It's by far the cheapest, easiest, and most convenient way to chlorinate. You will never look back.

 

[fastrunnerdude]

My skimmer doesn’t send any water back to my filter and pumps. It only recirculates back into the pool. All the returns to the filter and pumps go through the main drain so not sure if that makes a difference.

 

[PoolStored]

My skimmer doesn’t send any water back to my filter and pumps. It only recirculates back into the pool. All the returns to the filter and pumps go through the main drain so not sure if that makes a difference.

If it doesn't go through a pump, how does it recirculate? Post some pictures to explain.

 

[Newdude]

When pucks sit with no flow, they ooze acid sludge. It has eaten skimmers, plumbing, chlorinators, check valves and heaters many times on TFP.

Floating in the pool the breeze alone will move it around so it doesn't sit and cause a problem.

You can get away with using the feeder or skimmer, until you can't.

 

[fastrunnerdude]

I think this is the setup how my skimmer works I have a valve at my equipment that can take returns from the main drain in my pool, the skimmer, or partial flow from both. I normally keep it set to take 100% of returns through main drain and nothing back from the skimmer.

When my pump is running, water is pumped in below the skimmer basket creating a Venturi effect that pulls the water into the skimmer and directly back out into the pool as I tried to illustrate below. The return line to the filter and pumps has valve closed at equipment so nothing flows through it.

I put a couple pucks on the bottom of the basket below the bag and so the circulating water pushes it out into the pool.

 

[pjt]

My skimmer doesn’t send any water back to my filter and pumps.

You skimmer has to be connected to a suction line leading to a pump, otherwise it wouldn't work.

All the returns to the filter and pumps go through the main drain so not sure if that makes a difference.

This doesn't make sense. Post some pics of your equipment pad. The term "return" means the piping on the pressure side of your system returning water from your equipment pad to your pool.

 

[fastrunnerdude]

See my drawing of my Venturi skimmer in my post above. I had my terminology backwards but returns from my pump to the pool come through both the skimmer and the in floor jets.

This photo is not my pool but it’s an identical concept. The return running below the basket creates a suction that pulls water through the skimmer and the water is discharged directly into the pool.

 

[Newdude]

More plumbing = More. Reason. To. Not. Let. Acid. Sludge. Soak. In. It.

Running the pump 24/7 is fine, until the power goes out or the breaker phantom trips.

 

[proavia]

@erinkalogris3
Welcome to TFP!

• Trichlor tablets (stabilized tablets) add CYA
• CalHypo tablets (unstabilized tablets) add calcuim
• Either will build up in the pool and require draining water to remove.
• Do NOT mix either together in the same container or floater. Do not use the same floater for both.

@fastrunnerdude

• When (when, not if) the stabilized chlorine tablets damage the skimmer and/or plumbing, it will be an expensive fix to replace - thousands and thousands of dollars, vs a 10 dollar tab floater. Your pool your choice.
• Your venturi skimmer would work better with a bit of flow to the pump (presently closed valve).
• Set the skimmer/main drain 3-way valve to the 50%-50% position to increase the skimming action of your venturi skimmer. This will skim more and allow less stuff to settle to the pool floor, while providing sufficient flow thru the main drains to pick up stuff the IFCS sends their way. You may also be able to run your pump at a lower rpm (saving electricity) and have a cleaner pool.
• What is the purpose of having two pumps? Hopefully your PB did connect the IFCS to the main 2.7hp pump.

 

[Lake Placid]

@fastrunnerdude …this is why you don’t put trichlor tabs in a skimmer.


On the left is what’s left of a bypass from a Rheem heater. The silver circles on its shaft are what’s left of the spring that should have looked like the spring next to it on the right. To the right of the spring is a unitherm, or a thermal regulator.



Here’s a closeup of the unitherm…..

These items came out of a heater that was a year old. Oh yeah the copper heat exchanger was destroyed and leaking too, but I don’t have pictures of it. While the heater was a year old, it was actually in service for one season…which in this area is at most 8 months and more likely 5 for this homeowner.

What caused the destruction? A trichlor feeder that had no check valve installed upstream and the acid soup was backing up into the header of the heater….destroying the heat exchanger, bypass, and unitherm. The lesson….don’t ever put pucks in the skimmer or anywhere else where their acid soup has direct free access to destroy components. They will.

 

[TinFoilHat]

You have a QuickSkim like I do. Water returns to the pool via the in floor cleaning heads and through the venturi under the skimmer. There is no pump suction from the skimmer unless you turn it on. But even with this I never put any chemicals into my skimmer. At the very least that's why my skimmer baskets last many years (I'm on my second one in 23 years).

 

[fastrunnerdude]

@erinkalogris3
Welcome to TFP!

• Trichlor tablets (stabilized tablets) add CYA
• CalHypo tablets (unstabilized tablets) add calcuim
• Either will build up in the pool and require draining water to remove.
• Do NOT mix either together in the same container or floater. Do not use the same floater for both.

@fastrunnerdude

• When (when, not if) the stabilized chlorine tablets damage the skimmer and/or plumbing, it will be an expensive fix to replace - thousands and thousands of dollars, vs a 10 dollar tab floater. Your pool your choice.
• Your venturi skimmer would work better with a bit of flow to the pump (presently closed valve).
• Set the skimmer/main drain 3-way valve to the 50%-50% position to increase the skimming action of your venturi skimmer. This will skim more and allow less stuff to settle to the pool floor, while providing sufficient flow thru the main drains to pick up stuff the IFCS sends their way. You may also be able to run your pump at a lower rpm (saving electricity) and have a cleaner pool.
• What is the purpose of having two pumps? Hopefully your PB did connect the IFCS to the main 2.7hp pump.

Thanks for the feedback. The higher HP pump is a VS pump and controls the water features (sconces, bubblers). The lower HP pump (non-vs) circulates through the IFCS.

My skimmer collects plenty as-is but I could change the valve to have some flow from skimmer.

I didn’t realize the picks in skimmer could cause such a problem and I’ll get a floater for the times I supplement with pucks.

We built the pool before I found out about TFP.