DaJMasta

If there is livestock in there, I would definitely focus on supplementing to get to good parameters. Yes water changes can work, and yes it does seem like some alkalinity is lost when mixing a high-alk salt mix for a long time (maybe heat contributes too), but if you've got a decent sized (>20G) tank and stony corals, you will need to supplement something eventually, since the waterchanges to keep things up will be demanding. Nitrate being so low isn't ideal, but slow changes are better than fast ones. If it just became detectable, I would wait another few tests to see if it stays there or increases. In the long run, more nitrate is usually better, but if it's already on its way, there's probably not a reason to speed it along unless you're getting dinoflagellates or something.

Are you seeing any coralline growth? It sounds to me like there is starting to be some life in there and they are beginning to use and produce detectable amounts of things. Is there anything beside rock, sand, and water in there yet? I would supplement dkh with an additive and check again days or a week later, though a water change would help replenish it. If you have livestock already, I would try to feed/supplement to meet their needs and then figure out how to tune your filtration and export when they are happy and growing.

Flucanozole works for a lot of algaes, but I don't know if it works with dinos and by a look, I would say it's likely dinos or maybe some kind of cyano. I don't have much experience treating them, but I have heard that treatments can be pretty specific to the strain of dinos it is, so getting a sample under some magnification and asking in a dino ID forum is probably a good next step. Could the nutrient levels be out of whack? I've heard that particularly low nutrient levels can cause blooms and correcting that may be a starting treatment option.

Yeah I think the issue is when it's mixed up and comes into contact with air, then it slowly looses potency. Before that, as powder, I think you're good unless maybe it's stored open in a humid space or something.

Down to one larva of this age, have four that are about a month longer, but today is day 100 post hatch, and this is from a couple days ago:

Flattened bubble shaped egg sacs could be columbellid or collonista snails - if you can get some magnification on it, it may be easier to find out. Not sure about the flatworm, looks on the larger and more textured side to me compared to those AEFW shots, but I'm sure there are more than one variety and if it's a flatworm coming in on coral, there's a good chance it's a pest.

If you're not looking for "aquarium grade", you probably could still find it at Michaels or JoAnne Fabrics (going out of business?). Should just be "polyester batting", and with the thickness we're usually looking for, probably for quilting.

LiveAquaria has really dropped in quality in the last year or two, my last order, more than a year ago, arrived without even a styrofoam box, just loose packed in some crumpled paper (no additional bag around the fish bags either) with a heat pack. The bags were in the 50s, the cardboard box was thin (no impact protection), the crumpled paper was wet, and when I went to post about it on reef2reef, the responses I got were all similar experiences/sentiments. I hope they turn themselves around, but they are certainly not the quality they once were.

Another 18 days in, same larva (and still have the other one, it's just still smaller too.)

A baffle like a PVC pipe (or maybe if you need a flat side, a cleaned out food container with the bottom removed) should do well, just takes up some space and could potentially jam with certain critters getting into it (big snails.) You'd want it to extend an inch or two below the float (minimum, no max) to make sure any direct current was blocked, and you want it open on the top to prevent siphon related issues (not just an inverted cup.) Worth mentioning that it probably shouldn't be the long term solution, mechanical float valves have a few failure modes that makes them dump a lot of freshwater into your tank and they generally aren't known to be super reliable. If regularly inspected/replaced, they can probably work, but an electrical sensor with a backup sensor is a much more robust solution.

I don't know if it helps to catch both. She will protect him, but in isolation or with friendly tankmates that's not necessary, and it's quite beneficial for her to continue to eat a lot (helps grow the next batch) while he won't eat at all, so it made more sense to me to just catch him (and closer to hatch was my preference.) She may actually be more territorial/aggressive with him around carrying the eggs - mine has certainly mellowed out since losing her mate, and the peak of her acting like queen of the tank was always the time shortly before spawning and then I think near hatch.

I lost my male a year or more ago and that ended it. Still have the female, and spotted a fire shrimp one morning holding a full clutch of banggai eggs, so I am considering getting another male to introduce to her. He did start getting wise to my catching techniques after a few batches, though he also chilled out a little more and was a little easier to read (whether he was done spitting them out) the more times I did it.

Gonis have been a mixed bag for me too, the red one has always been happy, basically, and has either had long polyp extension or longer polyp extension. The green one in front is a somewhat lesser version of that. The nearly white nub sticking out behind the confusa on the right of the tank is actually a red short tentacle goni that for months now has looked bleached - pastel neon pink with some polyps, literally clear for others, but still extending... The red one has recently shaded out another short tentacle goni, and I had a couple others that didn't make it through some parameter swings or were put in too high lighting (it seems from my experience that short tentacle gonis don't like as much light), and I'm supplementing a small amount of manganese (not as regular as I should and no ICP in the last few months), that while I'm not certain is doing much, may have helped some of the ones with troubles hang on. As for SPS, I think this tank is gradually coming around too. I think my algae dosing was a bit a problem before - not actually doing it, but that I was overfertilizing the cultures and then dumping nutrients into the tank - and for a long time the monti top center was barely holding on. It's definitely happier, and it has some color (like the reddish acro on the left of it), but both only started getting happier in the last few months. I think it's probably also parameter stability related, since I had the calcium and alk swings due to dosing pump issues and not testing enough to catch them quickly.

It's been a while! The tank has been going along, largely happily, and is about a week shy of four years old now. A lot is unrecognizable, the coral cover is getting to a pretty good spot (trimming and warfare are common), but I've got some long time residents that seem to still be happy (including at least one hitchhiker pistol shrimp that still lives in tunnels under the rocks.) There have been too many events and changes to document, but some of the more recent ones include a crazing rigid airline in the vodka causing an air leak that stopped dosing for a bit (acrylic crazes in alcohol! polycarbonate does not!), a crack in the interface with the flexible airline in the soda ash doser that slowed that substantially (and let the alk swing down), the subsequent corrections to get it back in line, and in reference to above, a custom 3d printed algae scrubber which has been working pretty alright. As for issues, I've got one little stick frag that still isn't growing despite being in there for months, I have to clean the glass from film algae pretty much every day (maybe this is because of high phosphate, but a most-of-a-week long lanthanum chloride regimen didn't seem to do much), and these little clove polyps which look OK but have covered the majority of the rockwork and encrust over semi healthy corals. Not too much in terms of equipment failure, but I did lose a Nero 5 which I ended up just replacing. Still planning on opening the electronics package, but have a pile of other things to do. Oh, and I guess the fact that the red goni ended up with like 3.5" or more of tentacle length and started stinging all of its neighbors, then I corrected some parameters and they're probably past 5" now - not ideal in a tank that's like 18" front to back The pair of yellow banded possum wrasses spawn nightly, the mandarins I don't see spawning much now. The peppermints and skunk cleaners are still spawning but it looks a little less frequent than before, and if the fire cleaners are, I've been missing them. The banggai I have is still the same female and a few weeks ago I actually saw a fire cleaner holding a banggai egg mass, so I suppose I should find her a buddy, and the CBB and pintail wrasse bicker a little bit but seem to be good buddies. Green porites are more aggressive than darth maul porities

+1 to the above. No need to try and take things out when you're growing out the microbiome and are minimally feeding. I'd probably start with the skimmer around your first fish, and may actually wait for chemical filtration another little bit after that. I believe chemipure is supposed to take more stuff than carbon out - some of the inorganic metals and things - but there's a bunch of overlap. Both is probably the most comprehensive option, but just ROX carbon may still be plenty adequate, and if your stocking isn't too heavy and your water changes are somewhat regular, you may be fine with neither, though you'll have some water clarity benefits from it too.