Water changes

[info4lori]

This is going to be a long post, but the overall question is ... what do you do long term for water changes? I'm concerned about nitrates over the long haul.

This being my second attempt at keeping these little buggers, I finally feel some sort of success. My first attempt, back in 2018, sadly ended in wholesale shrimp death. All but 2 out of 20 survived. I told myself that I wouldn't get any more until I figured out what went wrong. Once I thought that I had it figured out (more on that later), I purchased 20 more from Mustafa in January 2020. The new ones are doing very well. In April and May, there were 5 to 6 berried shrimp and now I see a lot of little tykes. Today there are 3 or so more berried shrimps.

So what did I do wrong in 2018? Water changes. Lots of water changes. You see, I've kept tropical fish for many years, and one of the best things you can do for them is regular water changes. I thought that surely that would hold true for these guys. WRONG!!

I had read Mustafa's instructions very thoroughly before buying the first (unfortunate) little buggers, and I set up their little tank exactly according to instructions. I read that they didn't need or want water changes ... but I mistakenly thought that was advice to make things easier on the keepers, not the shrimp. Having had success with many types of tropical fish over many years, I thought surely the shrimps would also appreciate fresh (brackish, of course) water, and that I would go the extra mile and do that. Boy was I wrong. I did a 15-20% water change weekly (with clean, new brackish water), and over the course of 2018 most of the poor shrimps perished. I was so upset and confused about what went wrong. From what I understand now, these water changes likely messed with their molting schedule / ability. At the time, I noted that some of them had "the ring of death" (learned that term and what it meant sadly after the fact).

So back to the present ... all 20 shrimps I bought in January are flourishing and producing ... in the same exact tank and water I had set up for the original unfortunates. Only difference is, no water changes.

Which gets me to my question. Over the course of years, I imagine there will be a nitrate build up. Especially with the population increase. I feed very sparingly ( 1 micro pellet once a month). I'm aiming to keep these guys for many years to come. How do you control nitrate in a long term tank? Do you do very infrequent water changes? If so, how much water do you change at one time?

Thanks for your help!

[Dch48]

If you have healthy macroalgae and whatever other algae and biofilm might grow, it's possible to go extended periods without a nitrate buildup. My tank is over a year old now and the nitrates are zero. Having said that, a small water change like every 6 months or so wouldn't hurt. By small, I mean like a maximum of 5%. You may get by without ever doing one though as long as you keep a source of calcium like coral or cuttlebone in the tank.

[sfinster]

I have not heard of the "ring of death". What is it?

[mike.d]

I've had my tank for just over 3 years. There are two things I've never done:
1. Feed
2. Water change.

I have a standard Pet*/Walmart cheap 10 gallon tank. When my water level gets down a bit, maybe 1/2 an inch below the black plastic at the top. I add a half gallon of RO/DI water to top it off. That's every 3-6 months or so. The only other maintenance I've done is to clean the clear acrylic lid and pull out hair algae with aquatic planting tweezers. My substrate is aragonite.

I did add snails (MTS and 3 nerites) to help control the algae. I don't have macroalgae.

I've never heard of the "ring of death" either. Please enlighten with pictures, if possible.

[Dch48]

I don't have a picture but the "ring of death" is when a shrimp has a thin white band around it's body right behind the head. It's an indication that the shrimp is having problems molting and can't get out of the old shell. It's actually a separation in the shell exposing the body within. It's usual result is the death of the shrimp.

It happens when instead of the shell cracking at the top behind the head, it cracks all the way around. Then the shrimp will have a very hard time getting out of the old shell.

[mike.d]

Thanks! Some of my shrimp do have that, but I thought it was a natural coloration change. I found a video on YouTube: https://www.youtube.com/watch?v=9Z9Hn1RkuFI

None of my shrimp have died. Maybe they're hiding in the rocks someplace and dying there. But I'm not seeing any non-moving bodies, or body parts, and there are no clumps of shrimp and snails feeding on a carcass.

[Dch48]

Shrimp can also have white bands as part of their natural coloration. I have one Opae that does. If the band is right behind the head portion and looks like a depression, that can be bad. If it's further back or not depressed, it's just normal color and nothing to worry about. It's a known problem with freshwater shrimp but I don't know how often it happens with these guys. I would suspect not very often at all. Opaes are amazingly hardy and the brackish water just naturally contains more minerals than fresh.

[info4lori]

Thanks for all the comments so far.

Here's a good high level summary about the white ring of death: https://www.shrimpscience.com/articles/ ... -problems/

Although I can't be 100% sure, I'm reasonably sure this is what killed the first 18 out of 20 shrimps that I got in 2018. Although I used the same exact formula (1 gallon distilled water, 1/4 cup Instant Ocean) for the water changes as I had for the original water in the tank, I suspect that the TDS, GH, KH and/or pH was different between the new water and the tank water, which could have impacted their osmotic balance. I never took readings to compare old vs new water parameters, and I should have.

I'm reasonably sure the water changes were their cause of death because I put the shrimp that I got in January 2020 into the same exact tank with the same exact water that the 2018 shrimp lived in, and the new shrimp are doing great. The only thing that is different is that I stopped the water changes. If you have other thoughts on why they died, I'd be interested to hear them. Opaes are amazingly hardy and adaptable to temperature, salinity, and other factors, which is why I was so puzzled about their deaths. The white ring of death gives me a reasonable explanation, but of course there could be others.

My question, though, is around water quality and stocking levels. Assuming that all the juvenile shrimp live (they all seem to be thriving so far), my shrimp population has doubled from 20 to 40+ just since January. I have 3 more berried females as I'm writing this. They're literally breeding like rabbits. I'm not complaining (yet ) - I'm definitely excited. But at what point is my 1 gallon tank overstocked to the point that nitrates build up? And how can I mitigate that (other than move them to a bigger tank)?

I've kept planted tanks, still do, and at some point in the past I did a lot of reading on this topic. Many articles (some scientific) I read indicated that submersed plants don't always use nitrates as efficiently / quickly as they use ammonia and nitrites. This for various reasons, including CO2 and light limitations. That's why some aquarists use pothos or other type of emersed plant (leaves out of the water, roots in the water) to reduce nitrate levels. Works great. Unfortunately, I don't know of any small plant that I can grow emersed in brackish water. Mangroves get a bit too big My tank has Chaetomorpha macroalgae, which I assume uses some NH3 and NO2. Maybe even some NO3. But if I were to take a guess, I'd guess that it's like other emersed plants and it can't / won't use all the NO3 that a highly stocked tank can create.

I'm not worried about this for the short term (1-2 years). I'm worried about this over the long haul (5+years). Especially if the population continues to grow as quickly as it has been. Maybe I'm over worried, I don't know.

Thanks again for your comments, and please keep 'em coming.

[Vorteil]

I never change the water in my tanks. After years there's never any issues. I think my 6 gallon has more than 3k in it. They breed all the time and there;s never a day that I don't see babies floating around. I don't mess with this tank. I leave it be. My friends cube is over 15 years. No feeding or any water changes, only top off. Don't over think it. Set it up and let it run it course. It is that simple.

[mike.d]

But at what point is my 1 gallon tank overstocked to the point that nitrates build up? And how can I mitigate that (other than move them to a bigger tank)?

I'm thinking that's where the algae comes in. Nitrates build up, algae builds up, more shrimp (and snails, if you have them) eat more algae. That's how I've viewed my tank.

[Vorteil]

Ring of death pertains to the freshwater shrimp. I've never seen any issues with my Opae Ula. I don't use any additives vs the care I have to do for my Neo & Caridina FW shrimp. Complete opposite care. Although for me I will feed from time to time freeze dried spirulina to the tanks to help with the population increase. Not often at all. Maybe 1x every 2 months. All my tests are 0 but I don't test.