I have to appologize, my first post was a bit curt. I just get incredibly frustrated when people ask for help yet have no idea what they actually need help with.
OK, now that's out of the way... I have to agree with Nippy. Pikes are awesome fish! I have 5 different species at the moment.
Assuming that your Red Pike is
Cr. johanna plan on it growing to 12"+. I have found pikes to be relatively benign to other fish if they can't eat them... except for other pikes! Pikes are typically only really rough on other pikes. They are pretty intolerant of each other. That doesn't mean that they are pussy cats with other cichlids though. They will stick up for themselves and their territory. Typically, given enough room they are good tankmates. Nippy, I wonder, what size tank is your pike and RD in? I'm guessing 90 gallons or less based on your description of their behaviour. Large fish in tight quarters are more likely to lash out and act in such a manner.
Water parameters for
Cr. johanna should be soft, slightly acidic and as sodium free as possible. 78º-82ºF would be a good temperature range.
Large, frequent water changes and excellent biological filtration are required to keep the tank as free of disolved metabolites as possible since many of the large Lugubris group pikes are susceptible to HITH and poor water quality seems to contribute to the problem. Water high in dissolved minerals seems to play a role also. Hence the soft, acidic water recommendation (not to mention this simulates their natural habitat).
Diet should consist of meaty foods and foods high in protein. I have found that most pikes will eventually eat preparred foods. It may take some doing but it can be done. I currently have 3
Cr. acutirostris eating Marineland's new pelleted food. These three pikes were swimming in the Amazon less than two months ago. I supplement the pellets with beef heart, frozen krill, frozen blood worms and a product called Emerald Green which contains some greens (a little added fiber to flush out the digestive tract every few days doesn't hurt
).
Give them adequate space, good food and good water quality and you can expect something like this:
Here is also an excellent article on the giant pikes of the Lugubris group:
http://www.cichlidnewsmagazine.com/issues/oct2000/giantpikes.html
Hope this helps!!