My first aquarium (25 gal lagoon) is 3-4 months old now. Mostly zoas. Any advice?

hoochers · Nov 11, 2024

Here are pictures of my first aquarium after 3-4 months.

Still have not added any fish, I don’t really have a desire to. Also my rockscape doesn’t feel fish friendly since there’s no real hiding places. I got a bunch of zoas from a live sale on this forum that I just stumbled upon. I target feed the corals a light dusting of reef roids once a week the day before water changes. I also broadcast a half capful of aminos a couple times a week. I’ve read fish are good for reef tanks because the poop feeds the corals, but I’m lightly feeding the coral directly and there’s a lot of snails—and they poop all over the rocks too right? If I use the turkey baster on rocks there always gross stuff that flies off I assume is snail poop.

My sand had a daily coating of what I assumed were diatoms but they eventually stopped appearing a couple weeks ago. I’ve vacuumed the sand during weekly water changes from the start.

My rocks are still covered in what looks like some kind of brown/black sludge. I assume it is also some kind of diatom algae but not sure. Is it cyano? It doesn’t blow or scrape off the rocks. I have A LOT of snails (5 trochus, 7-10 Florida cerith, 2-3 nassarius, 2 mexican turbo (these are new I just wanted 1 for some ulva that was bothering my gsp frags, but it was a package deal), and they all munch on the rocks 24/7 but never seem to make a dent in whatever this algae sludge is. I’m just letting it hopefully run its course. Please chime in if you think I should do anything different. It doesn’t seem to bother anything, all my coral look happy and I haven’t had any snail deaths.

I am concerned that I may have too many snails now, and I don’t want any to die and wreak havoc on my tank (ammonia spike?). But I also don’t have fish, so is there a risk of snails dying and harming corals or other snails?

My water parameters have been pretty stable: salinity 35 (refractometer with 35 calibration fluid), temp 77 (IM helio heater + separate sensor in separate back chamber, both connected to one helio controller), alk 8.8 (Hanna), nitrates 6 (Hanna), phosphates 0.03 (Hanna). I don’t test cal/mag.

Mr. Mojo Rising · Nov 11, 2024

It looks great. My only comment is that, your nitrate/phosphate is very low, and without fish it might be hard to maintain measurable nutrients in the water to feed the corals, and the corals you have do like nutrients. Otherwise it looks great

hoochers · Nov 11, 2024

Mr. Mojo Rising said:
It looks great. My only comment is that, your nitrate/phosphate is very low, and without fish it might be hard to maintain measurable nutrients in the water to feed the corals, and the corals you have do like nutrients. Otherwise it looks great

Thanks! I’m confused though. I have nitrates (is this term replaceable with “nutrients?”) though. If I target feed the corals reef roids and broadcast feed aminos, and the snails are eating whatever algae and pooping it out, isn’t that all nutrients for the coral? I can easily increase the nitrates through this feeding (I also have neonitro to dose nitrates if ever needed) but I’m intentionally keeping it lower (through weekly water change where I vacuum the sand too) because I’ve read new tanks can go through wild swings as the bacteria and algae wars are waged through a tank’s first year.

littlebigreef · Nov 14, 2024

@hoochers Nitrates are a type of nutrient along with phosphates - so its a specific kind.

These nutrients, in turn, are an indirect measurement of the overall nutrition going into the system. As your system matures you'll work on dialing in your nutrient export (be it skimmer, cheto/macro harvesting in a fuge, biological, etc) so that your nitrates and phosphates stay in the Goldilocks zone while you adjust your nutritional input (ie aminos, phyto, coral foods, brine, fish foods, fish poop) as you add fish, corals, inverts and your microfauna get established.

Tank looks good and you're exercising good discretion. I wouldn't been too worried about snail deaths, if one goes just pull it out when you see it. On the whole they're pretty durable. As for fish I'd suggest looking at fire fish, royal grammas, some of the more durable smaller gobies. These smaller guys won't tax your bioload as the tank matures and you don't have to worry about them finding hiding places or pulling them out later.