MaxxStrip Tile Cleaning in Tucson

[JoyfulNoise]

Had the pool tile cleaned today using MaxxStrip (kierserite) blasting. The process is basic soda blasting technique coupled with kierserite media (MaxxStrip). The kierserite is the same Mohs hardness as calcium carbonate and so it is well matched to remove scale without damaging tile. Some photos of the process -

The “monster” truck with engine-driven air compressor -



The blasting process -









Results -

Before


After


Nuthin’ but crack -

 

[bdavis466]

Interesting.... My calcium is 1500 ppm and I have nothing on the waterline or spillway

How long since the last time it was blasted? If memory serves correct, 2-3 years?

 

[JoyfulNoise]

Interesting.... My calcium is 1500 ppm and I have nothing on the waterline or spillway

How long since the last time it was blasted? If memory serves correct, 2-3 years?

Yes, it’s been a little over 3 years. The scale on the spa face isn’t as hard as one might expect - I can scrap it off with a lot of force and my fingernail. So it’s definitely a mixture of salt, magnesium scale and calcium. I suppose you might call it evaporite rather than scale as it’s thickest in places where the water flows intermittently. The water line wasn’t really that bad; I’ve seen much worse pools where half the tile is coated with thick white scale. Mine was a 1/4” ring right at the water line that, funny enough, would disappear at night as the air cooled from dampness. You would see it more at the end of the day after the tile was really dry.

Do you run your spillway a lot? Do you use any ScaleTec or sequestering agents? I should probably run my spillway only at night or all day long so the water is always flowing on the tile instead of flowing for a short time and then drying up.

Tucson water is really quite bad in terms of hardness. The total mineral hardness (Ca + Mg) is high (220ppm and higher) and the carbonate alkalinity is 120ppm with high pH (7.8 and higher). That puts the CSI into very positive territory and so the water is prone to scaling (just look at my faucet aerators).

Also, my tile is not smooth but more of a matte surface finish so I wonder if the roughness enhances the scaling a bit more.

 

[bdavis466]

I'm all fake rocks and that has to be rougher than anything else out there. The spillway runs for 40 mins around 9pm.

No sequestrants and the only thing out of the norm would be borates at 80-100 ppm. I haven't tested that level in over a year so who knows what it is now.

 

[A165fun]

I’m a new pool owner. Is there a spray of some other stuff you apply and can scrub it off with a brush?

 

[JoyfulNoise]

I'm all fake rocks and that has to be rougher than anything else out there. The spillway runs for 40 mins around 9pm.

No sequestrants and the only thing out of the norm would be borates at 80-100 ppm. I haven't tested that level in over a year so who knows what it is now.

Yeah, I'll be increasing my borates later this season after I get my CH reduced. I really feel that borates do a great job at protecting the SWG cell and it's one of the reason why I never see scale in my cell; 50ppm is too conservative an estimate in my opinion. I have no animals that drink from the pool and, if the healthy bird population that poops all over my waterfall rocks is any indication, they seem to thrive on it.

I'll assume you keep your TA low and your pH in check. If I remember right, you are using an IntelliPH to dose acid, correct?? My pH tends to drift a bit (7.6-7.9) so my CSI does fluctuate over time. My salt is also a little high too (4000ppm) so I'm starting to think more and more that I'm getting a mixed evaporite deposit. I just changed my schedules around so that SPA mode (no heating) runs for an hour midday and the spillover only comes on at night. Perhaps if I keep the evaporation down, the spa face will stay a little cleaner.

 

[JoyfulNoise]

I’m a new pool owner. Is there a spray of some other stuff you apply and can scrub it off with a brush?

Dilute muriatic acid is always an alternative but your talking about A LOT of scrubbing and elbow-grease! There are also tile cleaning products that are a mixture of muriatic acid, phosphoric acid and hydrofluoric acid shock with thickener agents (sort of like toilet bowl cleaner) but you have to wear gloves and eyewear as the stuff is nasty and should never get on your skin. Finally, you can also use a pumice stone to scrap stuff off but that can leave scratches in the tile surface and you can't use pumice on glass tile so it's really only suited for cleaning grout.

Blasting is probably the most costly way to do it fast but it does make a mess. I guess at the end of the day the best advice is this -

An ounce of prevention is worth more than a pound of cure....

The more you can do to keep your pool water saturation balanced and tackle scale early, the better off you are. It's probably good idea during the season and at the end to get a spray bottle of diluted MA and just plan to spend an hour or two going around the pool cleaning off the tile.

 

[JoyfulNoise]

Water Chemistry Data

So I thought I'd end this thread with some useful numbers from my testing. Here are the test results before blasting (just looking at calcium hardness and total hardness, other parameters are either stable or have their expected variance from adding lots of fill water back in) -

5/17 (TH = total hardness and MH = magnesium hardness)

TH = 1560ppm
CH = 1320ppm
MH = 240ppm

5/19

TH = 1480ppm
CH = 1240ppm
MH = 240ppm

So, as you can see, the total hardness and calcium hardness of the pool water went down by 6.1% (using the CH numbers to calculate this) due to all of the draining, backwashing and refilling with municipal water (CH=180ppm & TH = 210ppm) BUT the magnesium hardness remained constant. So one has to assume that the blasting media, which is basically magnesium sulfate, added enough magnesium hardness to compensate for the drop in total hardness. One would also assume that the municipal water added to the magnesium hardness as well, but it’s pretty minimal. If you assume that the blasting media added it all, then that’s a conservative enough assumption. Since the hardness is measured in molar mass units of CaCO3, one can convert the 6.1% increase in magnesium hardness into magnesium sulfate and then determine the increase in sulfate concentration -

MH * 6.1% = 15ppm CaCO3 (this is the amount of hardness added by magnesium sulfate)

15ppm CaCO3 = 18.1ppm MgSO4

SO4 content added = 14.4 ppm in SO4 units

So then entire process increased my magnesium hardness by 6% and added ~ 14.4ppm of sulfates to the water. It's always best to keep sulfates low when one operates an SWG but 14.4ppm isn't very much and concrete studies have shown that one needs to be up around 300ppm before "sulfate attack" becomes a problem. Given that I will be draining a large portion of the pool water over the coming weeks, my sulfate levels will only go down.

All in all, while expensive to have cleaned this regularly (I only got 3 years between cleanings), the process does a good job with minimal impact on water hardness and sulfate levels. I hope this helps anyone who might be considering this process.

Here’s what Mr T cleaned off the bottom of the pool -

 

[Silver_2000]

I used my new pressure washer to clean our tiles

The turbo nozzle did a good job of cleaning 90% of the buildup

 

[JoyfulNoise]

I used my new pressure washer to clean our tiles

The turbo nozzle did a good job of cleaning 90% of the buildup

There are some who have tried that with little success. Water pressure can certainly help remove scale but you have to be very careful as the high pressure can easily strip out grout and, if your not lucky, can crack or knock off tile.

Most pool cleaners around here use glass media which is horribly abrasive. They then compensate for all the damage they do by sealing the tile with a glossy sealer. Unfortunately that makes the problem worse as the sealant yellows with age. The kierserite media is probably the best overall because it allows scale removal at reasonable air pressures (~ 90-120psi) with minimal damage to tile surfaces or grout.

Glad your pressure washer worked out for you.

 

[Silver_2000]

There are some who have tried that with little success. Water pressure can certainly help remove scale but you have to be very careful as the high pressure can easily strip out grout and, if your not lucky, can crack or knock off tile.

Most pool cleaners around here use glass media which is horribly abrasive. They then compensate for all the damage they do by sealing the tile with a glossy sealer. Unfortunately that makes the problem worse as the sealant yellows with age. The kierserite media is probably the best overall because it allows scale removal at reasonable air pressures (~ 90-120psi) with minimal damage to tile surfaces or grout.

Glad your pressure washer worked out for you.

My tile is relatively new and most is glass ... I was also careful

 

[JoyfulNoise]

My tile is relatively new and most is glass ... I was also careful

I bet. Glass tile is a whole other beast to tackle. Water alone probably is more successful due to the smoothness of the glass. On glass I would exhaust all chemical treatments before resorting to anything abrasive.

 

[pjt]

Would you mind sharing how much they charged for their service? I'm assuming they charge by the linear foot.

I have some scale/evaporite that refuses to go away despite trying many different methods and I'm considering MaxxStrip. Thanks!

View attachment 77960

 

[JoyfulNoise]

Would you mind sharing how much they charged for their service? I'm assuming they charge by the linear foot.

I have some scale/evaporite that refuses to go away despite trying many different methods and I'm considering MaxxStrip. Thanks!

View attachment 77960

I was charged close to $5 per linear foot and it was a 3-1/2 hour job. Three years ago I paid about $3.50/ft but the person that did that no longer services my area. Unfortunately what I have found is that tile cleaning is a bit of a “pick & choose” business as there are few people that do it and plenty of pools that need it. So the pricing is fairly steep since competition is non-existent. Also, in Arizona, these guys operate under the “handyman’s exemption” to the contractor laws so few, if any, carry any kind of insurance or need to maintain a license or bonding. So for them, it’s a nice cash business with just a little investment in equipment cost and maintenance. I’m not sure if CA has similar exemptions but you’ll want to carefully vet any tile cleaning service you contract or else they could leave you a mess with no recourse. The guy I hired was competent and fair and tried to do a careful and clean job.

Considering the costs involved, I really hope to go longer between cleanings and I’m going to be a bit more proactive on acid cleaning the tiles regularly.

 

[Teald024]

View attachment 77762

It looks like he did a good job. I bet he is the envy of his friends because he can say he gets paid to hang out in a pool all day. But looking at that pic, I'm sooo glad I don't have that job. That doesn't look fun at all...

 

[JoyfulNoise]

It looks like he did a good job. I bet he is the envy of his friends because he can say he gets paid to hang out in a pool all day. But looking at that pic, I'm sooo glad I don't have that job. That doesn't look fun at all...

Yeah, all told he was at my house for about 3-1/2 hours and in the pool at least 2 hours. There’s a lot of setup and cleanup afterwards. Once he was done blasting the tile, he vacuums the pool to waste (with his own separate water pump and vacuum) and dumps a nice pile of the MaxxStrip and crud out of the pool (over the wall in the easement between mine and my neighbors wall). After that he sweeps up everything, hoses down the tile and then goes around the pool hitting any small missed spots with pumice. He’s got it all down to a routine and, as he said to me, doing this is a “mental-health break” for him as he teaches middle school math all day. So I’m sure to some extent he enjoys it.

Plus he was paid handsomely in the end and was very happy to get his weekend spending money...