Salvaging 75 gal Fish Only tank with old technology

[Trailermann]

My very first post!
Picture this: heavily drilled acrylic tank, lava rock attached to three sides, UG reverse flow with crushed coral (circulated with Little Giant 2MD and passed through PEP paper filter cannister), two opposing and alternating current pumps (Little Giants 1MDs), 3/4" drain standpipes (2 each) down to wet/dry sump, and pumped back to a jet nozzle on water surface. Oh yeah, canopy hood with five T-12 HO actinic and daylight tubes.

So against all common wisdom, I want to get this set up back to life. You know, give it the old college try. I am prepared for failure, and know that at the very least, I will learn a ton and be ready to accept starting over in the right way.

To give myself a fighting chance, I plan to build a large, 35 gallon sump using my existing wet/dry bio-ball trickle tower, adding a decent skimmer, and having a lighted refugium section with DSB and algae. Also installing an old, never used Aquanetics 15IL UV. Finally, Adding one more standpipe drain.

Yes, RO water, frequent water changes, and regular power washing of the bio-balls. LED lighting of course.

What else should I add or do to keep the tank looking good and fish healthy? And maybe a few anemones and corals?

Use live rock rubble rather than crushed coral gravel for the tank floor? vacuum the tank "sand" floor? Add GFO, Carbon, and/or bio-pellet reactors? Maybe swap out the trickle tower for two filter socks? Lots of live rock along with the DSB in the refugium? More water flow?

 

[greech]

Congrats, welcome!!!!

Gonna need a pic. So is this a closed loop? Don't quite get the reverse flow UG. Holy cow, those pumps on that size tank! Seems inefficient but again I don't quite get the setup.

Lava rock is questionable and will likely become detritus magnets. They will need to be blown off/out frequently.

Wouldn't bother with the fuge unless you want it for decoration. By the time you part out a 35 gallon sump, the fuge section will be negligent. Focus on a good skimmer and give it a decent amount of water to sit in. Not a fan of the DSB either but up to you.

No need for bioballs (just more maintenance).

Don't use LR rubble for your substrate. You'll never keep it clean and you can't vacuum it (easily). Aragonite sand or nothing IMO. I vacuum my sand but others don't (not sure how they get away with that).

GFO and carbon reactors are worth the expense (particularly GFO) IMO.

 

[Trailermann]

Thanks for the helpful feedback. Let me better explain the plumbing (which I described wrong earlier). The first closed circuit starts from multiple screened outlets near the lower middle of the tank, but above the sandbed.
The water goes thru a pump, then the cannister filter, then back to the tank and is distributed evenly under the screened crushed coral. Next two sets of reversing currents. Each picks up from a pair of bulkheads near the upper center of the back, then thru a pump, and split back to two current fan nozzles. Finally two overflow standpipes drain down to a sump after trickling over bioballs. The sump water is returned to a jet just below the surface of the tank water creating surface agitation.

Are you saying the pumps I described are too big or too small? Since the pumps are rusted out, I can buy whatever sizes are best.

As for the sump size, 32 gallons is the amount of water and sand for the fuge. The sump will be 48" x 18" x 20" overall.
Because of the reverse nature of the "sandbed" crushed coral or similar is necessary. The tank "floor" is a fine mesh screen over eggcrate. What are the drawbacks of this if vacuumed regularly?

 

[greech]

I am not going to say it won't work but the rock and the mesh are going to be a problem from a detritus/nutrient perspective. It also looks like the rock is already pretty loaded down with organics which is going to be a challenge.

I see why you were using those externals now but there are more efficient pumps out there. Without powerheads (assume you can't use because of the rock), you'll need a lot of flow from the returns.

 

[Trailermann]

I am starting to get a better idea of what I am up against.