Hehehe.......Welcome to the fun world of MH bulb selection........it can be fun to play with and to experiment with to "tune" in your tank for just the right look and performance, or a pain to get a straight forward, clear cut answer.
If it were not bad enough that there are so many colors(K) to choose from, the vary from manufacturer to manufacturer....bulb to bulb, SE to DE, ballast to ballast.
You can supplement them with VHOs, T5s, or PCs to get a different effect and still add another variable by changing them colorwise.
This can be fun or a nightmare to tune in.
Things to think about:
1. You have 250s over a 100g correct.....this means weather you choose anything from a 10K to a 20K you will have enough PAR to keep stuff happy, healthy and thriving. This is the main reason I switched from 150DE to 250DE.....I wanted a bluer bulb and the choices were limited and the drop in PAR, just going to a 14K was so great I was having trouble keeping color.
2. New bulbs take about a week to break in and become there "true" color. In addition, your eyes may not be used to them yet. Give it a little time before you take them back......fired bulbs don't get much of a trade in....keep them for an emergency or sell them here if you hate them.
3. Look at other tanks in person and decide what "color" or "look" you want and ask them what they are using. I personally like the "silver" color of the 14K Ushios and have gone to the Phoenix 14K for a change and like it.
4. As mentioned, a basic rule of thumb......10Ks are really Yellow and in most opinions ugly, but on average have more PAR for faster growth. 20Ks have that cool ocean blue look that everyone likes but on average have less PAR. I agree and find 14Ks a nice balance between the two to get "the look" and performance for growth. The "performance" change from 10K to 20K is noticable but not dramatic.......if your growing for frags and want production, go with 400w 10K.......other than that, you have MH already and whatever bulb you like the looks of will probably be fine.
4. If your not familiar visit Sanjay Joshi's site for bulb info.....
http://www.reeflightinginfo.arvixe.com/index.htm
5. See what others are using and why they like them........having DEs, I can't be much help....but the old favorite is the Radium 20K, XMs, and Ushio, Reeflux, Geissman and Pheonix are a few others I believe the SE guys like.
Trial and error is the best way to find what you want and most people have a few bulbs lying around that they didn't like.....I know I do. I have found Marine Depot a good resource due to a large selection if you have not, check there
Oh yeah....they start to shift and loose PAR between 8 months and a year but based primarily on hrs per day used....I usually get bored and want to play with them every six months to try something new.
But going back to your original post, define "not liking the top" for your SPS placement.
FWIW I run 2-250DE which on average are more focused and intense than SEs over my 75g which is a shallow tank........I have a lot of pieces way up high.......I don't think you have "too much light" and it could be something else. If thats the reason for the bulb change......maybe we should address the SPS behavior first?
