Keeping dwarf shrimp in planted tanks

Introduction

There are many species of dwarf shrimp on the market today, with a staggering number of different color variants and color patterns. Some species have become very prolific in the hobby such as the ubiquitous and easy to care for Cherry shrimp "Neocaridina davidi", while there are other species with more specific requirements such Crystal red shrimp "Caridina Cantonensis" and Sulawesi shrimp "various Caridiana species". 

These shrimps are non-aggressive towards fish and their striking colors stand out in planted tanks. They also provide a visual treat as they forage for algae and detritus on plants and hardscape. While it may be difficult to observe such shrimp in the wild due to their small size, the aquarium provides the perfect setting for scrutinizing them up close.

Dwarf shrimps are scavengers that feed off organic detritus, algae and micro organisms. However, if you have a dead fish in the tank or uneaten fish food, they will also gather and attempt to consume it. In planted tanks, they perform the useful functions of breaking down organic waste and dead leaves and consuming algae.

Pros

- Aesthetic and colorful

- Consumes algae and breaks down organic waste

- Non-aggressive towards other livestock

- Breeds easily given suitable tank conditions

- Matches planted environment very well

Cons

- Sensitive to ammonia, water quality and parameters

- Prey to larger fish, especially shrimp fry

Tank environment

There are a few aquarium qualities that all shrimp prefer. Shrimps are small and delicate creatures. They prefer well cycled tanks with good water quality, and having a matured tank environment, with good filtration and biological stability is most important. Different species will also have specific requirements where water parameters are concerned. It is also good to have surfaces such as moss or rocks where biofilm have developed allows grazing spots for shrimp. Shrimp are often at the bottom of nature's food chain, and are prey for larger fish and other animals. This is especially true of baby shrimp and providing them with adequate hiding places in the tank greatly improves their survival rate in tanks where fish are also kept. 

In terms of requiring an environment with good water quality and biological stability, shrimps actually have a lot in common with what is optimal in a well run planted tank. We want a tank that has an adequate filtration and circulation (shrimp like well oxygenated water as with any other livestock). A well cycled tank where plants have been growing in for some time, and where no abrupt changes are made on a regular basis is ideal. This also means that introducing shrimp into a fresh planted setup on day 1 is a terrible idea. While shops may push for this in an attempt to sell whole planted systems in a single day, it is much better to allow the tank's biological system and plants to mature for a few weeks before introducing sensitive livestock such as shrimp. A planted tank goes through many significant changes when it is freshly setup; if aquasoil is used, the soil biology has to convert from a dry state to a submerged state, plants need time to adapt and grow in, and significant trimming/replanting of plants can occur. Algae may spawn and the hobbyist may choose to do larger size water changes on a regular basis for the first couple of weeks of a setup. The microbes in the soil and filter need time to develop. All these instabilities affect the tank's water quality in the initial weeks of a new planted tank setup.

Key points:

- Maintain good water quality by having adequate filtration and circulation, matured tank environment.

- Have adequate hiding and grazing spots. A well planted tank should have no shortage of either.

- Add shrimp to a matured setup, not on day 1.

Water parameters

Different shrimp have different water parameters requirements. Neocaridina species tend to be more robust and can be raised in a very wide range of water parameters from very soft-water to harder water. Caridina species tend to prefer softer, low KH water. Sulawesi shrimp prefers more alkaline water, along with higher temperatures. As a very general guide, cheaper shrimps are easier to keep and are more adaptable, while costlier shrimp tend to have more specific requirements and are harder to breed (Hence the higher market price due to reduced supply vs demand). Before you buy specific shrimp, check on the requirements for that particular species. 

A temperature between 21°C and 26°C is suitable for almost all dwarf shrimp species. Higher temperatures lead to a faster life cycle, which means quicker growth and more breeding but also a shorter life span. Sulawesi shrimp prefers higher temperatures; 26°C to 30°C.

As with plants and fish, it is much easier to keep shrimp that take to your tap water parameters. 

These are some generic guidelines for each Genus:

Neocaridina davidi shrimp (Cherry/Fire red/Bloody mary/Chocolate/Yellow):

pH: 5-8
GH: 3-15
KH: 0-12
TDS 50-400  
 
Caridina cantonensis shrimp (Crystal red, Crystal black):

pH: 5.5-7.5
GH: 4-8
KH: 0-4
TDS 50-300 

To read more on what does pH, GH, KH and TDS mean, head to the water parameters page.

While the stated ranges are enormous, it does not mean that just because your tank's parameters fall within the range that you can just buy said shrimp and drop it into the tank. Depending on how a certain batch of shrimp are breed, they will be more suited to those water parameters. 

Acclimatizing shrimps successfully to your tank parameters is an important step in ensuring their survival. Thus, it is best to buy shrimp from breeders that have similar water parameters to your tank. If that is not possible, get shrimps from a source where you can easily adjust your water parameters to match. A Bloody mary shrimp that has been bred in pH 5.5, 1dKH water will find it difficult to acclimatize to a pH 8, 12dKH tank. However, if you manage to find a source that has breed the Bloody mary shrimp in pH7.5, 8dKH, then the chances of successfully acclimatising them to your tank parameters of pH8, 12dKH will be much higher. 

More robust, easier to keep varietals like Cherry shrimp acclimatize more easily to parameters different from which they were bred, while more sensitive varietals such as Crystal red shrimp are best introduced to water similar to which they were bred in. 

CO2 injection

CO2 injection causes the pH of the water to drop, often by up to 1 full point. This does not affect shrimp as long as the underlying GH and KH does not change. (CO2 injection by itself does not change GH/KH values). Despite being touted often as an important value, pH fluctuations by itself, with no change in carbonates hardness, have little impact on livestock. To read more on pH fluctuations due to CO2, head here.

This tank has near 0 KH due to the aquasoil + very soft tap water. The pH drops about 1.4 points from 6.5 to 5.1 daily during CO2 injection. Bloody mary shrimp still breed like rabbits in this environment. Occasional feeding with shrimp food speeds up reproduction rates.

While hardier shrimp species (such as common Neocaridina and Caridinas) can breed in CO2 injected tanks, delicate species (generally higher priced species that have very specialized requirements) may be breed less readily when CO2 levels are cranked up high. Delicate species may also be more stressed by frequent large water changes and other disturbances to the tank environment. If you are worried about stressing delicate breeds of shrimp and want to focus more on breeding shrimp than on growing a large variety of plants, you can consider setting up a low tech tank with easier, lower maintenance plants. Such tanks are very easy maintenance-wise. Slower growing plants due to being non-CO2 injected means less pruning and replanting work, and less disturbance to the tank environment. 

A low tech tank with mostly mosses and easy plants is almost maintenance free. 30% water changes are done on this tank every couple of weeks, while the mosses are pruned only once in a couple of months. While the tank size may be a bit small for fish, the shrimp thrive in this planted aquascape.

Fertilization

The most common question asked with regards to fertilization is will copper in fertilizer hurt my shrimp? Copper levels in commercial fertilizers are too low to affect aquarium livestock. DIY mixes that overload on poor quality trace mixes may present an issue, but even then it takes a significant overdose. Most liquid fertilizers do not impact water parameters significantly enough to cause any issues even with delicate breeds of shrimp.

Water changes

Large water changes (say >90% of tank volume) by themselves do not affect shrimp or tank stability if the water used to refill the tank has parameters matching the tank water. However, in reality, there can be significant differences in water temperature or other parameters. Also, draining the tank to very low levels by itself can stress livestock. 

Hardier species such as Cherry shrimps or common CRS can withstand large water changes without issues. However, for more delicate strains, you might want to moderate your rate of water changes to say, 30% every 2 weeks. Low tech non CO2 injected tanks where growth rates and maintenance requirements are lower are great for breeding more picky shrimp species.

Conclusions

An optimized planted tank has many qualities that shrimps prefer also. The core quality that shrimp and plants both appreciate is a tank that is biologically stable with good water quality over the long term. The same things that trigger algae; big fluctuations, ammonia, uncycled tanks - are the same things that harm shrimp. The fears over fertilizers and Carbon dioxide affecting shrimp are often exaggerated by in-experienced folks; who lose shrimp due to a huge range of other poor practises than the 2 factors they blame. Delicate shrimp species have a significant mortality rate when handled by less than expert hands - with no correlation to either fertilization or CO2 usage.

The evidence of skilled planted tank growers being able to breed a large variety of shrimp species in their well fertilized, CO2 injected setups is increasingly common. However, it does require the mastery of both aspects; shrimp husbandry and plant horticulture skills.