Fry-proofing your tank is much like child-proofing your home with
the same drastic results if hazards are overlooked. I've heard it
said that fry seem to be on a mission to seek out anything that might
possibly hurt them. You must keep them away from heaters, filters,
and intakes of all kinds. Either use dividers or sponges to block
all dangerous items. Don't leave even a tiny gap as they will
either get through it or get their tail stuck in it. I've had
problems using filter material as it can create a "Velcro effect" with
the little seahorse spines. Avoid tankmates. Juveniles can
be housed with snails and small shrimp (and keep an eye on the shrimp).
The quality of your water is life or death to your fry.
Remember that there are many substances which we do not test for - be
absolutely sure of the safety of any decorations you might add to the
tank. Be sure to rinse all food items whether live or thawed.
Test at least the salinity, ph, ammonia, nitrite, and nitrate levels at
least weekly. Test for ammonia several times a day in nurseries
and daily in grow out tanks - ammonia is true poison to fry and you must
do as many water changes as necessary to keep it down. When our
fry were young and kept in unfiltered, un-cycled tanks we did as many as
4 water changes (20-30%) per day and larger changes when ammonia tests
showed it was needed. In cycled tanks less water changes will be
needed, but you must be obsessive about testing. Water quality may
also become a problem when you first start offering frozen foods which
may not be eaten - so pay close attention.
Hydroids are one of the most dreaded of problems when it comes to
fry. Hydroids come in several forms from "dots with legs" on the
glass to long cob-web looking things on rocks and plants. Hydroids
sting and kill fry. For this reason, most people avoid live sand
(also hard to keep clean), live rock and even macro algae in nurseries.
Panacur can be used to kill hydroids but it will also kill corals, some
snails, starfish, and other inverts - the effects of panacur can last
for many months. Macro algae can be rinsed with hydrogen peroxide
then rinsed in freshwater, then rinsed in saltwater to be sure no
hydroids are present. Hydrogen Peroxide is very dangerous to all
living critters for a limited time, however, once it breaks down into
water and oxygen no lingering effects are present. Rock can be
treated in the same manner or boiled however it will be dead rock at
that point and will need to slowly build the nitrifying bacteria colony
you need. Hydroids can be
introduced with the BBS as well - decapping brine eggs will avoid that
possibility also rinsing the brine before adding to the nursery.