With the caridina shrimp I’m trying to keep the KH around 30 ppm CaCO₃ (about 1.7 dKH) by pre-treating Cambridgeshire tap water with a suitable amount of hydrochloric acid (HCl).  The problem is the old aquasoil has been resisting the new water chemistry.  The other problem is the aquasoil is brown/black and the slate is also dark which makes the whole setup kind of dark and the shrimp challenging to see.  I decided to clear out the old aquasoil and replace the active substrate with inert sand.  This was also a good excuse to see how the shrimp population was doing and to clear out and treat any nasty looking pieces of hardscape.  I also figured the foam pieces in the base of the Shrimphaus that were supposed to act as a kind of passive under-substrate filter were probably not actually doing anything useful, so I took those out.

Sand is better than  aquasoil

Replacing the aquasoil as substrate I decided to go with Hugo Kamishi quartz white sand which I picked up from Aquarium Gardens.  This sand has very uniform sized grains from 0.8 mm to 1.2 mm in size which is considerably smaller than the aquasoil spheres.  One pleasant surprise was how much easier it is to plant plants in sand compared to aquasoil.  With aquasoil it is difficult to get the plant to not spontaneously float up again after you install it.  With the sand though, you grip the plant with pinsettes, drop it down into the sand, swoosh around a small bit to get it settled, and you’re good to go.  The aquasoil was also reasonably “mobile” for whatever reason.  It would roll around and down into the deeper parts of the tank and basically not stay where you put it.  The sand doesn’t seem to do that.  I understand that aquasoil has all kinds of nutrient goodies and buffering capacities… yadda yadda yadda, but I think I’d rather just have direct control over what’s happening in the aquarium water.

If you get sand and want it to be chemically inert, you need to be really sure you’re getting quartz and not for example marble or limestone based sand.  These non-quartz sands can potentially leach carbonate into the water raising the pH and KH.  My advice is spend a little more and get a really nice grade of professional aquascaping quartz sand.  

Shrimp love rocks

I got this great book for Christmas:  The Neocaridina Shrimp Handbook – a comprehensive guide by Richard James.  Most of the info in there I was already pretty familiar with, but one piece got my attention, “The one thing neocaridina shrimp do appear to appreciate is good pile of rocks.”  In his experience, for whatever reason, breeding seems more successful when there is a pile of rocks in the tank.  Something about hiding places for the new hatchlings maybe?  In any event I figured let’s go with some piles of rocks.  I got some Wio ‘black venom gravel’ which is nice rounded pieces, most very dark when wet, and built up a few rockpile areas.  One is between the two slate pillars that hold up the river, and another is on the left size keeping the sand away from the pump and heater.  Wio claims these are “pitch black when wet” which in my experience is not quite true… also the odd piece does have some whitish stripes or patches.  Mostly though they are very nice and contrast well with the white quartz sand.  Do shrimp really love rocks?  Difficult to know although they do spend some time in the rockpiles.  I also buried the airstone under the rocks which keeps the airstone from getting scunged over with algae – the bubbles still make it up through the rocks just fine.

Hugo Kamishi white quartz sand

Wio black venom gravel

New setup with sand and rocks

I got the old Shrimphaus completely cleaned out.  It was actually not so bad… not nearly as nasty as Shrimphaus 1.0 was when I cleaned that out.  The shrimp seemed to mostly take the relocation in stride.  There were one or two that seemed a little traumatised, but ultimately the move went smoothly with no casualties.

cleaned out tank

top view

size view

The new setup is very similar to the old setup with two slate pillars to hold up the slate river so water flows up from the bottom back left and across the river to the top front right.

Shrimp-friendly filter

I used to have a nylon mesh over the pump intake with the idea of keeping shrimp from inadvertently pulled through the pump.  After a while that didn’t seem necessary so I took it off.  Then I had a crop of baby shrimp that just slowly disappeared and got to wondering whether the pump was a factor.  Just in case I installed some aquarium pump sponge around the pump.  I was concerned the sponge would make the pump too big to fit in the restricted space at the back of the Shrimphaus, but seems no problem.  Unintended, but it also occurs that the sponge will be able to act as a sort of ‘mini filter’ in the style of air-lift sponge filters except instead of using rising bubbles to pull water through the sponge the water pump just does that directly.  I figure it can’t hurt and might help.  We’ll see if it gets all crusted over with debris eventually, but so far so good.

Shrimphaus 3.0

Here’s the new look.  I like it!  The shrimp seem pretty happy as well and I expect (hope?) that not having the substrate influencing the water chemistry will provide more stability which is supposed to be important for shrimp ¹.

¹ Actually, I’m not really convinced stable water parameters are important for shrimp.  This is the common claim but I haven’t seen much direct evidence.