Exactly how does overfeeding kill shrimp?

wendyjo · Post by **wendyjo** » Fri Oct 20, 2006 6:29 pm

I am just wondering about this. I understand that uneaten food can pollute the water, but exactly how? If the tank is cycled then it's not a matter of ammonia spikes like it would be in an uncycled tank, right. So what exactly is the cause of death in those cases?

I lost a female on Monday and was told I was overfeeding. The tank is pretty new so I know that I must supplement. I cut back and didn't feed again until last night, a very small amount, and today I have lost another female. So I am just trying to figure this out. I only have 1 female left now and 2 males so if I lose this last female then my population will be gone.

I am feeding flakes, btw, and I don't see anything nasty like copper in the ingredients.

Neonshrimp · Post by **Neonshrimp** » Fri Oct 20, 2006 7:25 pm

Hi wendyjo,

First off, sorry to hear about your loss and the possible loss of your population

I know that overfeeding, even in a cycled tank, causes a bioload greater than what the beneficial bacteria and even plants can process. This will lead to the buildup of the toxic compounds. The shrimp are sensitive to these toxins and will be poisoned by it. When shrimp are weakened to a point by stress or poison they will usually not recover and die.

Are you sure your losses are due to overfeeding? I hope that the rest of your population makes it past the crisis. Please keep us updated.

wendyjo · Post by **wendyjo** » Fri Oct 20, 2006 8:07 pm

No, I'm not sure it's from overfeeding - that was the the only explanation that I got tho, from Mustafa. I got the shrimp from someone who breeds them and frequents this forum so I don't think they were sick or too stressed. One did die in transit, but the rest seemed fine and even had some babies (they were berried when I got them, which was about a month ago). I don't see any of the babies anymore either and there were at least 15 of them at one point

If overfeeding was the issue, causing bad water quality and a strain on the bioload, would it result in ammonia readings when doing water tests? Cause I am paranoid about water quality in such a new tank and test the water every other day. I had one day about 2 weeks ago when I had a very slight ammonia reading of .25 ppm the day after rinsing off my filter (in old tank water) and doing a light gravel vac. I immediately did a small water change (no vac) and added some Bio Spira and the next day the ammonia was back down to 0. I use Prime, which is also supposed to keep ammonia from being toxic, so I assumed that having such a slight ammount of ammonia in a tank with Prime wouldn't be an issue. It was about a week later, this past Monday, when I lost the first female and then I lost another today. These shrimp seem fine up until they die - eating well and their color is very good - they have colored up and grown quite a bit in the month that I've had them.

I know my tank is small - 2.5g. But is that too small for such a small amount of RCS? I started with 5, plus the babies that hatched, and there are 2 MTS in the tank as well. But as I said, except for that one day, the ammonia and nitrite readings are consistantly at 0, nitrates never higher than 5, Ph steady at 7.4, and temp between 74-76 degrees.

I am just trying to figure out what I may be doing wrong. And if I am overfeeding then how often should I feed? I don't want to starve them either. I have a java fern, another small plant (dunno what it is) a small amount of java moss, a peice of driftwood, and a large rainbow rock in the tank. The substrate is gravel with a bit of crushed coral, and there are a few small pieces of cuttlebone in there and a few peices of magnolia leaf. There is a bit of brown algae on the tank walls (diatoms?) and some green algae on the rock. The snails help alot with the algae.

I don't know what else to do or not do.

wee-one · Post by **wee-one** » Fri Oct 20, 2006 8:40 pm

test water for nitrates . too high nitrates vill kill shrimp .

wendyjo · Post by **wendyjo** » Fri Oct 20, 2006 8:45 pm

I posted above that nitrates have never gone above 5 ppm.

wee-one · Post by **wee-one** » Fri Oct 20, 2006 8:49 pm

did you get big rock from fish store ?

wendyjo · Post by **wendyjo** » Fri Oct 20, 2006 8:54 pm

Yes, from a pet store. It was dry, not out of a tank. A rainbow rock. Here is a pic of it:

wee-one · Post by **wee-one** » Fri Oct 20, 2006 8:56 pm

to me sounds like bad shipment of shrimp . could be sick before you get

wendyjo · Post by **wendyjo** » Fri Oct 20, 2006 8:59 pm

I honestly don't think so - I got them from a member of this forum.

Post by **Mustafa** » Fri Oct 20, 2006 11:01 pm

wendyjo wrote:No, I'm not sure it's from overfeeding -

Overfeeding is the most likely culprit from everything you are telling us so far...see below for more.

If overfeeding was the issue, causing bad water quality and a strain on the bioload, would it result in ammonia readings when doing water tests?

No. Food by itself won't necessarily cause an ammonia spike, and even if it did, it would be turned into nitrate quickly if your tank is cycled. animals produce ammonia, but your shrimp were not even eating much of the food. Overfeeding has cumulative effects....chemicals that we don't usually measure for can acumulate in the water over time....all of a sudden a population that has been doing well can start deteriorating without you having changed anything recently. However, you had been doing something wrong, i.e. feeding too much and letting the food sit around for hours, already from the the beginning. It just took some time for the bad effects to accumulate to dangerous levels. Also, bacteria blooms can affect water quality and shrimp well-being. Food that is just lying around for hours can cause that. Many things that can affect shrimp cannot be tested (or can be with difficulty only) by the average hobbyist.

If you just follow the advice given in the articles and the forum, then your shrimp will be fine. Leaving the food in the tank for a few hours is a big no, no...same with giving food to shrimp that don't settle down on it and start eating it within a short amount of time. You should not worry about the shrimp starving....there is enough food for shrimp in a cycled tank...especially for just a handful of shrimp as in your case.

There is also no set amount of food that you should feed. Just follow the basic rule...if shrimp jump at the food right away, then feed it....if not, then don't feed and take the food out. You will get the hang of this after a while...it does take a little bit of experience to figure out how much to feed. That's really all I can say about this.....and again...just read, read, read...do your research and you will eventually be able to keep shrimp alive over several generations.