Backup lights

[pseudorand]

What affordable lights can I keep on hand in case my lights die?

Requirements:

1. Keep sps alive for 2-3 weeks while I shop/purchase/ship/install a replacement for a hypothetical failed led fixture.
2. Cheap -- I can't afford $1k+ unused backup fixture.
3. Reliable -- I'll test them when I first get them, but I want to be able to take them off the shelf years later and expect them to work.
4. Easy to install and/or small enough to pre-install -- What if my lights die on vacation? I need to be able to tell my non-reefer friend/neighbor/relative who's watching my tank how to turn them on. Ideally, something small enough to sit along side my existing LEDs so it can just be plugged in would be ideal. But how much would constant exposure to salt splash, etc. decrease the odds that they actually work when I need them. Even better is something I can put on my controller so I could remotely turn them on/up, but I'm guessing anything I can connect to a controller will be on the pricey side.

My DT is a 120, 60" long. My main lights are 4 x Lumia 5.2 mounted on 2 x 2' Maker Heatsyncs on a DIY controller based on raspberry-pi. This has all worked out great for the 1.5 years since I installed it, and I have an awesome sunrise/sunset lighting schedule. I have never taken a PAR reading.

I also have some dim spots that I'd like to illuminate. The heat syncs should be able to handle more LEDs, which is why I bought them in the first place. But it took me weeks of tinkering, returns and exchanges, both for defective equipment and stuff I know I damaged and had to replace. Now that I have corals (not the case when I was building it), I don't dare touch anything for fear it will take me weeks to get it running again. So step 1 is some sort of a backup that can keep things alive while I tinker. It is, of course, a good idea to have something on hand anyway in case of unexpected failures.

My current fixtures are centered in the tank, so I have about 5.5" on either side. that I could install additional fixtures in. I think I could pre-install a 2xT8 fluorescent fixture dirt cheap, but:

• Is there an easy way to make it point towards the center of the tank since it will be on the side?
• What T8s do I use, and any guesses as to how 4xT8 compares to my 4 x Lumia 5.2?

I'd also prefer a dimmable solution so I can turn them on in the middle of the day both to get a bit of extra light and continuously verify that they're in good working order.

Does anyone else have backup lights on-hand? What do you have?

 

[pseudorand]

I'm tempted to just buy cheap commercial T8 fixtures, mount them on a slightly angled piece of wood bolted to my canopy and stick this on the back. Parabolic reflectors may be better, but I can only seem to find them in the 100+ quantities.