[pEEshEE]

I was hoping someone could give me some feedback about switching over to bare bottom. I recently acquired, from a friend, a 90 gallon RR tankthat was primarily a FOWLR setup. The problem is that the 3-4" DSB my friend was using is a mix of crushed coral, shells, and other various live sand, which is probably why I can't seem to lower my nitrates below 30-40ppm.

Over the past week or two, I've pretty much changed out almost 85 gallons of water with no reduction in nitrates. I changed about 40 gallons when we moved the tank over to my place. I tested the nitrates - 40. 2 days later, I started to change 5 gallons/day for the next 4 days at which I tested the nitrates again...30-40.
The rest of the water parameters are within optimal ranges. I started to slowly transfer over some coral from my nano tank from day one, mainly softies, and all is well so far. I also dropped in one squamosa from my nano, and also so far so good (actually in my 25 gallon sump/refugium).

I've decided I will start to slowly siphon out some sand every week with water changes.

My question is for a 90 gallon, how many powerheads, and how much flow should I have for the bottom of the tank? I plan on upgrading to a metal halide in the near future with maybe a few sps thrown in whenever I can get my nitrates down. Currently, I have a Yellow tang, Saddleback clown, Algae blenny, Arceye hawkfish, and a juvenile Clown trigger... yes, yes, I know the Clown trigger is a no-no... but he's the main reason why I got the bigger tank. It sounds crazy, but I think I can train the little bugger to behave. So far, he's hasn't even touched any of the snails, crabs, or sand sifting star, and hasn't nibbled on any of the coral... so we'll see how it goes. (If he starts to turn into the mean fish he's pegged out to be, then I'll make a decision at that time)

I was also maybe thinking of just keeping a small amount of sand, just to barely cover the bottom, for aesthetic purposes.

Any recommended brands for powerheads? Flow rates?

Thanks.

	SPS Small Polyped Scleractinians - Sometimes known as Small Polyped Stony corals. These are hard corals that have extremely small polyps. They are typically on the difficult side and require Metal Halide lighting or dense Power Compact or T5 arrays. These corals are prized for their rareness and ability to be easily fragged into multiple colonies.

[Deanos]

Going barebottom tips

Water Changes in Reef Aquaria

[pEEshEE]

Awesome, thanks!

[reefman]

don't b surprise even bare bottom u may still have 40ppm nitrates. there may be other contributions to this. assuming ur test kits r reliable.

[pEEshEE]

I guess I should retest my RO water before I make the move... but what other factors might be contributing to the high nitrates?

[PVsPlayhouse]

A dead fish in the tank that you cant find. Or anything else that mite of died. What you can do is run a powerhead through all your rocks and see if anything is there. It will also kick up anything that mite be laying on top of the sand. Put in a filter sock or something to get anything that comes up. Change your water after you are done. Then do 25% water changes a week for a month that will bring it down.
For Flow if you have a SPS tank it should be 30 to 50 Turns per Min. If softies you should try for 20 to 30 turns. You should not have direct flow as well. I would use a Tunze. If to much then get a Seou (SP).
I would keep the sand not only for looks but for all the little life that is in there. You can do a sand bed of 2 to 3" But I would have at least 3".

	SPS Small Polyped Scleractinians - Sometimes known as Small Polyped Stony corals. These are hard corals that have extremely small polyps. They are typically on the difficult side and require Metal Halide lighting or dense Power Compact or T5 arrays. These corals are prized for their rareness and ability to be easily fragged into multiple colonies.

[pEEshEE]

Cool. Thanks for the reply. I just did my weekly water change of 25-30 gallons, but this time, I siphoned out about 10lbs of substrate. I checked nitrates, and for the first time since I took possession of the tank, nitrates fell to 20ppm! I'll check in a few days to see if it remains stable. If so, then I'll siphon out a bit more next week... if not, I'll take out even more sand, I guess.

I'll update on my progression.

[tangerine]

Quote: Originally Posted by PVsPlayhouse For Flow if you have a SPS tank it should be 30 to 50 Turns per Min. If softies you should try for 20 to 30 turns. You should not have direct flow as well. I would use a Tunze.

not sure i understand this. 30-50 turns per Min?? as in turnovers? if so,how to get this kind of turns?

	SPS Small Polyped Scleractinians - Sometimes known as Small Polyped Stony corals. These are hard corals that have extremely small polyps. They are typically on the difficult side and require Metal Halide lighting or dense Power Compact or T5 arrays. These corals are prized for their rareness and ability to be easily fragged into multiple colonies.

[PVsPlayhouse]

Quote: Originally Posted by tangerine not sure i understand this. 30-50 turns per Min?? as in turnovers? if so,how to get this kind of turns?

Yes, Trunover sorry about that. You take the amont of flow in your tank and dived it by tank size.
EX. GPH/Tank size. So if you have 3000GPH in a 100gl tank you are getting 30 turnover in a hour. I made a mistake in my last post it is 30 to 50 turns per hour.

[ShaunW]

Quote: Originally Posted by pEEshEE Cool. Thanks for the reply. I just did my weekly water change of 25-30 gallons, but this time, I siphoned out about 10lbs of substrate. I checked nitrates, and for the first time since I took possession of the tank, nitrates fell to 20ppm! I'll check in a few days to see if it remains stable. If so, then I'll siphon out a bit more next week... if not, I'll take out even more sand, I guess. I'll update on my progression.

I personally don't think you should convert to BB slowly. You need to do it quickly without any corals present in the tank.

Once you introduce oxygen to the deeper layers of the sandbed your going to have a HUGE die off in anaerobic bacteria and potential release of H2S. This will affect your coral in a negative way. IMHO.