Raising pH in Large Fish Only System

[CoralCrib]

So I've got a store in Illinois, where I have a 500 gallon fish only system. It's got no sand bed and no live rock, just PVC shelters and bare bottom acrylic. We sell out of the system, so I want it to be as sterile as possible, however without sand or rock the pH stays very low (around 7.5-7.6). We tend to have some problems keeping fish long term as well, and I believe pH would have some affect on it.

Is there any way to raise pH consistently? Maybe a fluidized sand bed? Or dosing on the fish only system?

Also, am I correct to assume this low pH is harmful for most reef fish?

 

[InactiveAcct]

Usually it’s too much CO2 in the indoor environment. Easiest way is to run an airline from outside to the skimmer, if possible, being mindful not to have the airline exit anywhere stupid and having activated carbon in line with it.
A fuge with chaeto, etc, may help but probably isn’t desirable in this particular system.
Raise alkalinity to 8 or higher, it buffers the ph.
That said, I’d be surprised if these deaths are a ph issue. More inclined to think its malnourishment (starved to keep nutrients low or otherwise unacceptable food) or disease issues (velvet, flukes, etc)

 

[CoralCrib]

Usually it’s too much CO2 in the indoor environment. Easiest way is to run an airline from outside to the skimmer, if possible, being mindful not to have the airline exit anywhere stupid and having activated carbon in line with it.
A fuge with chaeto, etc, may help but probably isn’t desirable in this particular system.
Raise alkalinity to 8 or higher, it buffers the ph.
That said, I’d be surprised if these deaths are a ph issue. More inclined to think its malnourishment (starved to keep nutrients low or otherwise unacceptable food) or disease issues (velvet, flukes, etc)

Yeah I'm thinking the dosing will be the way to go. They are certainly not malnourished, if anything we feed too much.

 

[brandon429]

agreed with Dan

the only way to rule out disease is to be quarantining each fish before they're held in that tank. mixed together, its got the transmission rate of any standard weekend bender at studio 54 in 1978. it didnt use to be so likely but something in the sourcing/transfer system brings disease into play to account for the vast majority of unexplained losses especially when sustained over time/repeating. that ph should be protecting against ammonia issues vs higher ones anyway

when fish only systems lack surface area in direct contact with the display waste water, there can be buildups before the water is taken down a drain into the appropriate contact zones then pumped back again. I guesss if your ammonia meter is ok that's not in play