Re: Substrates: Sand

You wrote: 

>From: HoeschB at mail_fws.gov
>Date: Wed, 19 Apr 95 10:45:14 MST
>Subject: Substrates:  Sand
>     A few comments on the use of sand as a substrate for plants.
>     I bought a 100 pound bag of sand from the local hardware store 
for $4. 
>     I believe it is usually used for making concrete.  It is light 
>     brown and flecked, not blinding white like beach sand, and looks 
>     and natural. It passed the acid test; I put some in a jar with 
>     and it did not change the pH.  It was rather a chore to clean, 
>     took quite a few rinses. 

I found the stuff certified for use in sandblasting in Calif. looked as 
you describe yours, perhaps a bit more pale and gray, but had already 
been well washed. The extra cost (about $2-3) seems well worth it, for 
washing sand is a nuisance. I, too, don't like the bleached beach look.

I think they remove the fine dust to meet OSHA requirements for low 
silica inhalation.

> Now I have my tank set up with 
>     sand/laterite/Tetra Hilena-D and am still seeing beautiful growth 
>     months after set up. (Several types of large and small swords, 
>     indica, Hygrophila polysperma). An advantage is that the root 
>     grow rapidly to enormous size.  This is also a disadvantage, 
>     the bigger sword plants are impossible to move without disrupting 
>     entire tank.  I just pulled up a huge Echinodorus cordifolius and 
>     quite a mess --it had roots 18 inches long.   In the future I 
>     have to decide from the start where large plants will be 
>     located.  Even small plants like E. intermedius or quadricostatus 
>     deeply and are hard to pull up without making a mess.
>     A possible disadvantage might be the lack of water circulation 
>     the fine particles.  We will have to see what the long term 
>     is. 

Has anyone else tried my trick? I bought fiberglass cloth (usually used 
for making boats or pools) and placed it over the UGF plates. That way, 
finer sand (mine was 30 mesh) doesn't fall thru the slots, and a much 
more gentle flow over the roots is maintained. I, too, added some peat 
between sand layers and finished the top with acid-treated Lone Star 
medium aquarium gravel, just for appearance. Lots of water changes were 
required to remedy an original fertilizer error.

The results have been fairly spectacular. With a DIY CO2 going in each 
end of the 55G, the plants have all gone wild, with one exception. I 
was unaware that Java moss was an estuarine plant and actually needs 
some salt in the water. It did OK as soon as I moved it out of the warm 
(81F), soft (50ppm), acid (pH 6.2-) tank and put it in a hard, slightly 
brackish, livebearer tank.

Otherwise, this seems to be an amazingly healthy tank. So far, I have 
managed to rescue a few eggs and have a half-dozen Jordanella floridae 
fry. The parents plant a few more eggs every day. One of the two pairs 
of Apistogramma macmasteri has a cloud of 100+ babys hidden in the 
hygrophila, and just today, I noticed that the Corydoras paleatus that 
I got from Sean Lev-Tov are plastering eggs all over the glass. The 
other pair of Apistos is looking for a place to spawn, too. I don't 
know what long-term stability will be, but, so far, this is the 
happiest tank I have ever organized.

The Amazon Swords are totally out of control. A few weeks ago, I 
weighted some runners down, and the offshoots are now over 8" high. The 
two main plants are reaching the surface of a tall 55G, and must have 
50+ leaves each. Light has been bad. I hated to remove the thick 
duckweed and salvinia, because I knew I was throwing away floridae 

>     Someone (Erik, I think) mentioned that sand substrates are bad 
>     Corydoras, but I have not seen this.  I have a shoal of Corys 
>     love to root about in the sand, and their whiskers are intact.  
>     types of sand may have this problem, but not this stuff.

The misunderstanding about the difference between glass, fused silica, 
and silica in the form of quartz continues to surprise me. Quartz is an 
obelisk-shaped crystal, with all obtuse corner angles. It should not 
hurt the most delicate barbels. SiO2 sand is mostly quartz and other 
similar silicates.

The longest healthiest barbels I have ever seen were on Sean Le-Tov's 
Corys. They were raised on a substrate of what appeared to be almost 
pure silica sand. He was justifiably worried when I wanted to put some 
obsidian in my tank, but the stuff I use is well ground off and smooth 
to the touch, so it has been no problem. 

>     That's enough rambling for now. 

For me too. :-) 
>     A big round of kudos to Shaji and the others who started this 

I'll second that. Thanks folks.



What if the Church and the State are the mob that howls at the door?
                                            --  William Butler Yeats