Steve Goodale isn’t used to attention like this. It’s not that he’s unfamiliar with being on camera: His YouTube Channel, Swimming Pool Steve, has amassed nearly 91,000 subscribers covering topics like how to bond concrete and clean a used hot tub.

But the saga of the Lincoln Memorial Reflecting Pool, which an algae bloom turned green following a renovation that President Donald Trump’s administration claimed would make the pool “American flag blue” in time for the US’s 250th birthday celebrations, has left people searching for answers about what the heck is going on.

The mystery has only deepened as chunks of the newly installed lining have appeared to break off and Trump has said the pool will be drained while, without evidence, blaming vandals for the problems. Add in US Park Police arresting people for touching the water like it’s some kind of biohazard, and that’s made Goodale, an award-winning pool expert, one of the most in-demand sources for anyone trying to figure out what’s happening to the iconic monument.

Pools are in Goodale’s blood: He learned the tricks of the trade from his Uncle Joe and refers to pools as “a family business.” I called him up to go over some of WIRED’s most burning pool questions. This interview has been lightly edited for brevity and clarity.

WIRED: Are you sick of talking about all this yet?

Steve Goodale: This is like the Simpsons episode where the devil force-feeds donuts to Homer. “So, you like talking about pools, do you?”

“We heard you like talking about pools, so we’re going to give you pools 24/7. All the time.”

I’ve been talking about them forever. It’s just now everybody is listening.

You’ve gotten a lot of reporters calling you and asking, what exactly is wrong with the Lincoln Memorial pool. But from watching your videos, it sounds like it’s hard to say there’s one definitive thing wrong with it.

There’s not enough information, in terms of pictures, videos, water chemistry values.

A natural pond, an open-air, clear water environment—that’s what this thing is—there are so many moving parts here. It’s the structure, it’s the water chemistry, it’s filtration. There’s so much stuff that has to work in conjunction with each other.

I’ve been saying for decades now, I think swimming pools are the origin of the term “doesn’t hold water.” If you don’t do every part of your job properly, it’s very easy to see that there’s something going wrong.

Experts like you can see 101 ways in which a project like this could fail, even with a very talented, experienced team doing the renovation.

Pools are mercilessly complicated—and I’m talking about little ones. This is literally monumental in size. It would take a master class in technical execution to be able to work on this thing in a competent capacity.

But you don’t need Swimming Pool Steve to tell you that when you see what appears to be the interior surface peeling up and floating in chunks, that’s an “oh, crap” moment.

I’ve seen some speculation that the hydrogen peroxide might be the cause of the bottom of the pool peeling. But you made a video about the lining, saying that it might be more complex than just that.

There is merit to this line of thought. These interior surfaces, they’re very chemically resistant, but they’re not infinitely chemically resistant. It would come down to what’s being used, and what concentrations of it are being used—all these unanswered questions.

But with a membrane system like this, there’s a lot of technical points you have to nail during installation. You have to account for ambient conditions like rain, sun, humidity, moisture control in your substrate, thickness, evenness, and chemical compatibility There are so many things that can go wrong with that process. If the material hasn’t bonded to the substrate for any number of reasons, then ultimately, the entire system will fail.

Now the president is claiming that it’s vandalism.

I can’t really get my head around the mechanism of vandalism that could cause this kind of damage. In terms of pictures and videos, it doesn’t look good, but it was fairly localized stuff. I haven’t seen anything that shows the 250-foot gash. At this point, I’m sure you can understand I, more than anybody, have questions, too.

The Department of Interior keeps saying “we’ve got the nanobubblers on, that should fix it.”

Nanobubbler technology is an ozone injection system—it essentially adds oxygen to the water. In theory, it’s used as a suppression system to kill algae directly, but it also has a secondary function of making an oxygen-rich environment in the water, which controls the release of phosphorus from the sediment layer at the bottom of the pool, the primary nutrient source for algae.

Will sediment at the bottom of the pool affect the blue color? Or is it scattered too thinly to affect it?

It certainly starts thin, but it has the potential to be a heavier layer. It really comes down to the quality of the source water being used and the design of the filtration system itself.

Water from the Tidal Basin is usually pumped directly into the pool, but when there’s a lot of algae in the basin, they switch to municipal drinking water. The administration hasn’t answered our questions about what the source of the water in the pool is right now.

I’ve also been trying to find answers to that. But the water that’s in the pool is really what matters here. Now that it’s in the pool, what’s the phosphate level? What’s the nitrate level? Those would be good things to know.

So just grab a little bottle of water to test?

Well, I’ve seen on the news that maybe you can’t even get near it any more. But in theory, yes, if this were my swimming pool, I would walk right up to it, dunk my little bottle into it and take a sample. I would test for phosphates, and it would tell me an awful lot about the nutrients available for algae to grow.

In the big picture, how much of a mess is this to clean up? How much could it cost taxpayers?

I can’t speak to cost or budget issues. But I can tell you that draining a 6.5 million gallon body of water is certainly a considerable thing to do. In terms of what it’s going to take to fix it, what really matters at this point is, how much damage are we talking about here? Is it a localized area that can be exposed and repaired? Or is this an indication that there’s some sort of systemic issue?

You have to look at it as a system as a whole.