Maintaining stability in nano systems

[LittleFidel]

Hi all,

I have two nanos that I would like chemistry guidance with.
The first is a 20 gallon with hang-on-back filter. Inhabitants include 2x ocellaris, 1x royal gramma, 2x echinopora lamellosa frag, very small assorted CUC, live rock, and caulerpa prolifera and red gracillaria for nutrient export.


The second is a 29 gallon with hang-on-back filter. Inhabitants include 1x favia frag, pulsing Xenia colony, eco complete planted tank substrate, a significantly sized mixed CUC, and lots of caulerpa prolifera for nutrient export.

I rarely test the parameters on the 20g as its inhabitants have been healthy for about 2 years.

The 29g, however, is less than one month old and I have been testing parameters to get a grasp of how saltwater tanks respond to different conditions. Ammonia, nitrite, and nitrate have been undetectable since startup. Phosphate remains low (.02ppm). Alkalinity is currently 187ppm and salinity gets as high as 40ppm before top-up water is added. I use tap water to top off and always have, for both tanks.
I rely on occasional water changes to replenish micronutrients and maintain stability for both tanks, but have no set water change schedule. I base the 20g changes on detritus accumulation, and have not determined the best plan of action for the 29g.
I am not immediately concerned about the quality of life for any inhabitants but would like to maintain the health of both systems as best I can. Please let me know any advice.

 

[elysics]

What are you planning on keeping in the bigger tank? Letting salinity rise to 40 and then dropping it down to 35 again, worst case doing so in one go, seems like it would be super harsh on the inhabitants. If you don't have the ability to top off more often, you should look into getting an automatic top off system, even if it's just one of those gravity fed bottle things you refill every couple days.

 

[hds4216]

An ATO is a huge help with salinity stability. The key to stability is testing often, and changing water or dosing when params begin to get out of wack.

 

[LittleFidel]

What are you planning on keeping in the bigger tank? Letting salinity rise to 40 and then dropping it down to 35 again, worst case doing so in one go, seems like it would be super harsh on the inhabitants. If you don't have the ability to top off more often, you should look into getting an automatic top off system, even if it's just one of those gravity fed bottle things you refill every couple days.

I am not sure yet. I was considering just transferring the inhabitants from the 20g over. I don’t want more fish; they steal food from the corals when I try to feed them and provide enough movement as is, to be honest. I’d like to convert the 20g to a quarantine tank but would also be open to the idea of using it as an ATO.

 

[LittleFidel]

An ATO is a huge help with salinity stability. The key to stability is testing often, and changing water or dosing when params begin to get out of wack.

I am most concerned with salinity at the moment. Whenever I top off in order to maintain salinity, I know it causes huge swings in other parameters. I am measuring alkalinity but don’t even measure others like magnesium, calcium, etc. Because the top off water to maintain salinity makes it hard to analyze data.

 

[Nano sapiens]

As mentioned, an ATO is really helpful in maintaining stability (the smaller the system, the more important IMO). It can also function as a doser for Kalkwasser (which is what I do) so that alkalinity and calcium are added in small amounts over extended time (promotes proper pH stability, especially).

IME, having a regular maintenance routine (and sticking to it) is also quite important for stability. If you don't have one, the system doesn't get used to a routine (stability) and it's really hard to figure out trends over time.

 

[blasterman]

Kept smaller tanks for decades and never used an ATO. There is simply too little displacement for a potential malfunction to make a mess.

Let me repeat. I've had 10 gal tanks with wall to wall SPS and not used ATOs and just manually dumped water in it when the waterline got low. Never a problem. Polyps don't even retract on acropora when I dumped 1/2 gallon if fresh water in it.

ATOs are an automation tool. They have nothing to do with tank health, dont cure covid 19, etc. Fish do not need counselors if your child taps on the tank.

Also, fish only get stressed when going from low density to high density water, and it has to be a big jump at that. In a typical top off scenario you add fresh water and reduce density of the water.

I've seen only mention of one lps coral, and we are already talking about dosing. You do not need to dose these tanks.

For long term tank health dont over feed, keep your water changes on a regular basis, check nitrate now and then, and quarantine new fish.

 

[LittleFidel]

Kept smaller tanks for decades and never used an ATO. There is simply too little displacement for a potential malfunction to make a mess.

Let me repeat. I've had 10 gal tanks with wall to wall SPS and not used ATOs and just manually dumped water in it when the waterline got low. Never a problem. Polyps don't even retract on acropora when I dumped 1/2 gallon if fresh water in it.

ATOs are an automation tool. They have nothing to do with tank health, dont cure covid 19, etc. Fish do not need counselors if your child taps on the tank.

Also, fish only get stressed when going from low density to high density water, and it has to be a big jump at that. In a typical top off scenario you add fresh water and reduce density of the water.

I've seen only mention of one lps coral, and we are already talking about dosing. You do not need to dose these tanks.

For long term tank health dont over feed, keep your water changes on a regular basis, check nitrate now and then, and quarantine new fish.

Your last paragraph has been my go-to strategy for the 20g that has been running for 2 years, and it has seemingly worked well. When I have the urge to test nitrate, I usually do phosphate and alk because I am still learning more about these two parameters. Is there anything else I should be investigating? Thanks for the conservative approach.

 

[Nano sapiens]

Kept smaller tanks for decades and never used an ATO. There is simply too little displacement for a potential malfunction to make a mess.

Let me repeat. I've had 10 gal tanks with wall to wall SPS and not used ATOs and just manually dumped water in it when the waterline got low. Never a problem. Polyps don't even retract on acropora when I dumped 1/2 gallon if fresh water in it.

ATOs are an automation tool. They have nothing to do with tank health, dont cure covid 19, etc. Fish do not need counselors if your child taps on the tank.

Also, fish only get stressed when going from low density to high density water, and it has to be a big jump at that. In a typical top off scenario you add fresh water and reduce density of the water.

I've seen only mention of one lps coral, and we are already talking about dosing. You do not need to dose these tanks.

For long term tank health dont over feed, keep your water changes on a regular basis, check nitrate now and then, and quarantine new fish.

I've been keeping small reef tanks since my first 'built from scratch' one in 1984 (8g display, 12g sump).

While we each have our own opinion based on our own experiences (and what we've observed in other systems over the years), what I can say is that my current 12+ year old 12g is the first one I've had with an ATO (gravity fed pet bottles) and it has been the most successful. Also, I have never had any malfunction with these bottles, but it is true that mechanical ATOs can and do fail on occasion.

You might say that success can be due to 'other factors' than having an ATO and I'll grant that many things need to come together properly to create a thriving reef tank. But I personally attribute at least part of it's doing well to the stability provided by the ATOs.

Another thing to consider is that you may be diligent topping off your systems' replacement water by hand, but others might not and go a week or two (or more?) without doing so. Relatively large swings in salinity are tolerated by some of our typical hardy corals, but not all. Undoubtedly any coral would be less stressed (and do better) with a stable salinity.