% Water Change and Glue

[Hawaii kai]

Aloha, two questions for the experts out there:

• Is there anything wrong with doing a 50-70% water change if NH4 or No2 spikes? I have a 60 gal Unicube and I just had a spike when I added a large crab. The tank is fairly new ~50 days so I don’t think I overloaded it yet just needs to readjust. We live on a seawater marina and my son catches fish with a net off our dock to stock the tank. When I do a water change I just use the marina water. I have been doing this for about a year with a smaller tank and now that I moved up to a bigger tank I’m wonder if it is ok to do large water changes during spikes.

• Is there any good glue to use inside the tank to glue decorations together?

Thanks

[tholleyh46]

They sell epoxy to adhere corals and the like to rocks, I'm sure you can use it for other decorations too. Comes in a tube, its kind of like JB Weld (two colors of clay) that you mix together and then once mixed fasten away. As to your other question, I have done 50% or so water changes without much problem, just do it over a slower amount of time and it shouldn't be too much trouble. However, when you import live critters and water directly from the ocean I have heard that you run a risk of bringing contaminants and diseases directly into your tank (can't say I'm not guilty of doing the same on occasion though). Also, beware that large crabs (even small ones with large claws) will catch and eat your fish. I caught a scorpion fish once (tiny) and introduced him to the tank along with a really small crab. Eventually, the crab caught the scorpion fish and trying to get the crab out of the tank (from under the rocks) was quite a trick. He just sat on the substrate with his claws up waiting to catch some dinner. Unfortunately, I didn't notice until it was too late. Hope you don't experience a similar event. The Mrs. wasn't so happy with me that day.